SEC Info℠

Home

Search

My Interests

Help

Sign In

Please Sign In

Banco Santander, S.A. – ‘F-4/A’ on 8/6/19

On:  Tuesday, 8/6/19, at 4:23pm ET   ·   Accession #:  1047469-19-4575   ·   File #:  333-231581

Previous ‘F-4’:  ‘F-4/A’ on 7/31/19   ·   Latest ‘F-4’:  This Filing

in

this entire Filing. an “Entity” Search.

Show

Documents searched

and

each “hit”. the 1st “hit”.

↓↑Hints

 Text Wildcards:  ? (any letter/digit),  * (many).  Search Logic:  for Documents:  & (and),  | (or);  for Text:  | (anywhere),  "(&)" (near).  Details... 

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 8/06/19  Banco Santander, S.A.             F-4/A                  3:1.6M                                   Merrill Corp/New/FA

Document/Exhibit                   Description                      Pages   Size 

 1: F-4/A       Pre-Effective Amendment to Registration Statement   HTML   1.17M 
                by a Foreign Issuer for Securities Issued in a                   
                Business-Combination Transaction                                 
 2: EX-23.1     Consent of Experts or Counsel                       HTML      7K 
 3: EX-23.2     Consent of Experts or Counsel                       HTML      7K 

Use these links to rapidly review the document
TABLE OF CONTENTS

Table of Contents

As filed with the Securities and Exchange Commission on August 6, 2019.

Registration No. 333-231581

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Amendment No. 3
to

Form F-4
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

BANCO SANTANDER, S.A.
(Exact name of Registrant as specified in its charter)

Ciudad Grupo Santander
28660 Boadilla del Monte (Madrid), Spain
Telephone:+34 91 289 32 80
(Address, including Zip code, and telephone number, including area code, of Registrant's principal executive offices)

Banco Santander, S.A.
New York Branch
45 E. 53rd Street
New York, New York 10022
Attn: Mercedes Pacheco, Managing Director and Senior Legal Counsel
Telephone: (212) 350-3500
(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:
Nicholas A. Kronfeld
Marc O. Williams
Davis Polk & Wardwell LLP
450 Lexington Avenue
New York, New York 10017
Telephone: (212) 450-4000

Approximate date of commencement of proposed sale to the public:
As soon as practicable after this Registration Statement becomes effective.

            If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

            If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

            If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

            Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer)    o

            Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)    o

            Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933.

Emerging growth company    o

            If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards† provided pursuant to Section 7(a)(2)(B) of the Securities Act.    o

CALCULATION OF REGISTRATION FEE

(1)

American Depositary Shares ("Santander Spain ADSs") representing ordinary shares, nominal value €0.50 per share ("Santander Spain ordinary shares"), of Banco Santander, S.A. ("Santander Spain") registered hereby have been registered pursuant to a separate registration statement on Form F-6. Pursuant to the U.S. exchange offer to be made by Santander Spain (the "U.S. exchange offer"), Santander Spain ordinary shares and Santander Spain ADSs representing such Santander Spain ordinary shares will be offered and sold pursuant to this registration statement to (a) all holders of American Depositary Shares ("Santander Mexico ADSs", each representing five Series B shares ("Santander Mexico shares") of Banco Santander México, S.A., Institución de Banca Múltiple, Grupo Financiero Santander México ("Santander Mexico"), par value Ps.3.780782962 per share) and (b) holders of Santander Mexico shares that are U.S. holders (within the meaning of Rule 14d-1(d) under the Securities Exchange Act of 1934, as amended (the "Exchange Act")). Pursuant to a separate exchange offer to be made by Santander Spain in Mexico (the "Mexican exchange offer"), Santander Spain ordinary shares will be offered and sold to holders of Santander Mexico shares.

(2)

Represents the maximum number of Santander Spain ordinary shares expected to be offered and sold pursuant to the U.S. exchange offer, and a portion of the Santander Spain ordinary shares that are to be offered and sold outside of the United States in the Mexican exchange offer that may be resold from time to time in the United States or to U.S. persons, calculated in accordance with the exchange ratio of 0.337 of a Santander Spain ordinary share to be received for every Santander Mexico share.

(3)

Computed solely for the purpose of calculating the registration fee pursuant to Rule 457(c) and Rule 457(f)(1) under the Securities Act. The proposed maximum aggregate offering price was calculated in accordance with the exchange ratio of 0.337 of a Santander Spain ordinary share to be received for every Santander Mexico share and was based on the market value of Santander Mexico shares, calculated by taking the average of the high and low prices of the Santander Mexico shares as reported on the Mexican Stock Exchange on July 25, 2019, converted into U.S. dollars based on an exchange rate of Mexican Ps.19.1315 per U.S.$1.00, the selling exchange rate reported by the Mexican Central Bank on July 25, 2019, and the average of the high and low prices of the Santander Mexico ADSs as reported on the New York Stock Exchange on July 25, 2019.

(4)

Computed in accordance with Rule 457(f) of the Securities Act by multiplying the proposed maximum aggregate offering price by 0.0001212. $218,123 of the registration fee was paid on May 17, 2019 and the remainder was paid on July 29, 2019.

            The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until this Registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

 C:     

†

The term "new or revised financial accounting standard" refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

Table of Contents

The information in this preliminary offer to exchange/prospectus is not complete and may be changed. A registration statement relating to these securities has been filed with the U.S. Securities and Exchange Commission and these securities may not be sold until the registration statement becomes effective. This preliminary offer to exchange/prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state or other jurisdiction where the offer or sale is not permitted.

Subject to Completion Dated August 6, 2019

Preliminary Offer to Exchange/Prospectus

Offer to Exchange
each
Series B Share and American Depositary Share
of
BANCO SANTANDER MÉXICO, S.A.,
INSTITUCIÓN DE BANCA MÚLTIPLE,
GRUPO FINANCIERO SANTANDER MÉXICO
for
0.337 of an Ordinary Share (for each Series B Share)
and
1.685 American Depositary Shares (for each American Depositary Share)
of
BANCO SANTANDER, S.A.

            Banco Santander, S.A., a company organized under the laws of the Kingdom of Spain (which we refer to as "Santander Spain"), will make an exchange offer (the "U.S. exchange offer") pursuant to this offer to exchange/prospectus and a separate exchange offer (the "Mexican exchange offer" and together with the U.S. exchange offer, the "exchange offers") pursuant to other offering documents published in Mexico and made available to all holders of Santander Mexico shares to acquire all the issued and outstanding (i) Series B shares (which we refer to as "Santander Mexico shares") of Banco Santander México, S.A., Institución de Banca Múltiple, Grupo Financiero Santander México (which we refer to as "Santander Mexico") and (ii) American Depositary Shares (each of which represents five Series B Santander Mexico shares and which we refer to as "Santander Mexico ADSs," and together with the Santander Mexico shares, the "Santander Mexico Securities"), in each case other than any Santander Mexico ADSs or Santander Mexico shares owned directly or indirectly by Santander Spain, in exchange for 0.337 of a Santander Spain ordinary share for each Santander Mexico share and 1.685 Santander Spain American Depositary Shares (each of which represents one Santander Spain ordinary share and which we refer to as a "Santander Spain ADS"), which will be in book-entry form or will be evidenced by American Depositary Receipts (which we refer to as "Santander Spain ADRs"), for each Santander Mexico ADS.

            We refer to the Santander Spain ordinary shares and Santander Spain ADSs collectively as the "Santander Spain Securities".

            No fractional Santander Spain ADSs or Santander Spain ordinary shares will be issued in connection with the U.S. exchange offer. Instead of any such fractional Santander Spain Securities that a tendering holder would otherwise be entitled to receive, the U.S. exchange agent will aggregate all fractional Santander Spain ordinary shares or Santander Spain ADSs (or the underlying Santander Spain ordinary shares) that all tendering holders tendering through the U.S. exchange agent would otherwise be entitled to receive pursuant to the U.S. exchange offer, sell such fractional Santander Spain ordinary shares or Santander Spain ADSs (or the underlying Santander Spain ordinary shares) at such times, in such manner and on such terms as the U.S. exchange agent determines in its reasonable discretion and pay the resulting net cash proceeds in U.S. dollars to such tendering holders.

            Santander Mexico paid a dividend on Santander Mexico shares on May 28, 2019 of Ps.071357065370 per Santander Mexico share.

            Santander Spain will declare the first interim dividend to be paid against its 2019 results with a record date yet to be determined. Santander Spain expects that settlement of the exchange offers will occur prior to that record date such that holders of Santander Mexico Securities that tender into the exchange offers will receive the first interim dividend. In the event that the settlement of the exchange offers occurs after the aforementioned record date, Santander Spain will amend the exchange ratio in the exchange offers to provide for a positive adjustment for tendering holders of Santander Mexico Securities to reflect the value of the first interim dividend and any subsequent Santander Spain dividends not paid to them. In the event that Santander Mexico pays any dividend after the May 28, 2019 dividend with a record date prior to the settlement of the exchange offers, Santander Spain will amend the exchange ratio to provide for a negative adjustment for tendering holders of Santander Mexico Securities to reflect the value of such Santander Mexico dividends. In the case of any amendment to the exchange ratio, Santander Spain will announce the new exchange ratio and, if required pursuant to Securities and Exchange Commission (the "SEC") rules, extend the expiration date for both exchange offers.

            The U.S.$/Ps. exchange rate on August 2, 2019 was U.S.$1.00 = Ps.19.3044.

            This offer to exchange/prospectus relates to the U.S. exchange offer and is being sent to all holders of Santander Mexico shares that are residents of, or located in, the United States and to all holders of Santander Mexico ADSs, wherever located. Separate offering documents relating to the Mexican exchange offer are being published in Mexico and made available to all holders of Santander Mexico shares. SANTANDER MEXICO ADSs MAY NOT BE TENDERED IN THE MEXICAN EXCHANGE OFFER.

            The exchange offers are being made on the terms and subject to the conditions set forth in this offer to exchange/prospectus under "The Exchange Offers" beginning on page 60 and the related letter of transmittal.

            Among other conditions, the exchange offers are subject to the approval by the Comisión Nacional Bancaria y de Valores (the "CNBV") for the registry of the shares of Santander Spain in the Registro Nacional de Valores (the "National Securities Registry" or "RNV" by its Spanish acronym) and their listing on the Mexican Stock Exchange (the "MSE").

            THE U.S. EXCHANGE OFFER AND WITHDRAWAL RIGHTS FOR TENDERS OF SANTANDER MEXICO ADSs AND SANTANDER MEXICO SHARES WILL EXPIRE AT 1:00 P.M. EASTERN TIME (12:00 P.M. MEXICO CITY TIME) (THE "EXPIRATION TIME") ON                , 2019 (AS SUCH DATE MAY BE EXTENDED, THE "EXPIRATION DATE"), UNLESS THE U.S. EXCHANGE OFFER IS EXTENDED.

            Santander Spain ordinary shares are listed on the Spanish Stock Exchanges in Madrid, Bilbao, Barcelona and Valencia ("SSE") under the symbol "SAN." Santander Spain ordinary shares are also listed on the London Stock Exchange ("LSE") under the symbol "BNC", the unsponsored Sistema Internacional de Cotizaciónes of the MSE under the symbol "SANN" and the Warsaw Stock Exchange under the symbol "SAN." The Santander Spain ADSs are listed on the New York Stock Exchange ("NYSE") under the symbol "SAN." The Santander Mexico shares are listed on the MSE under the symbol "BSMXB." The Santander Mexico ADSs are listed on the NYSE under the symbol "BSMX." Santander Spain will submit an application to list the Santander Spain ADSs that will be issued pursuant to the U.S. exchange offer on the NYSE. Santander Spain has submitted an application to the CNBV to register the Santander Spain ordinary shares to be issued pursuant to the Mexican exchange offer with the Mexican National Securities Registry and has filed for the Santander Spain ordinary shares for trading on the MSE. On August 2, 2019, the closing price of Santander Spain ordinary shares listed on the SSE was €3.755 (equivalent to U.S.$4.17 based on the exchange rate as published by the European Central Bank on such date) and the closing price of Santander Spain ADSs listed on the NYSE was U.S.$4.14. On August 2, 2019, the closing price of Santander Mexico shares listed on the MSE was Ps.26.93 (equivalent to U.S.$6.98 based on the U.S.$/Ps. exchange rate on such date), and the closing price of Santander Mexico ADSs on the NYSE was U.S.$6.93.

            As of June 30, 2019, Santander Spain owned, directly or indirectly, approximately 75% of Santander Mexico's total capital.

            See the "Risk Factors" section of this offer to exchange/prospectus beginning on page 26 for a discussion of various risk factors that you should consider before deciding whether or not to tender your Santander Mexico shares and/or Santander Mexico ADSs into the U.S. exchange offer.

            Neither the U.S. Securities and Exchange Commission (the "SEC") nor any state securities commission has approved or disapproved of the securities to be issued in the transactions described in this offer to exchange/prospectus or passed upon the adequacy or accuracy of this offer to exchange/prospectus. Any representation to the contrary is a criminal offense.

The date of this offer to exchange/prospectus is                        , 2019

Table of Contents

TABLE OF CONTENTS

i

Table of Contents

        This offer to exchange/prospectus incorporates by reference important business and financial information about Santander Spain and Santander Mexico that is contained in their filings with the SEC but which is not included in, or delivered with, this offer to exchange/prospectus. This information is available on the SEC's website at www.sec.gov and from other sources. For more information about how to obtain copies of these documents, see the "Where You Can Find More Information" section of this offer to exchange/prospectus beginning on page 11. Santander Spain will also make copies of this information available to you without charge upon your written or oral request to Morrow Sodali at 509 Madison Avenue, Suite 1206, New York, NY 10022. In order to receive timely delivery of these documents, you must make such a request no later than five business days before the then-scheduled expiration date of the U.S. exchange offer. This deadline is currently                , 2019 because the expiration date of the exchange offer is currently                , 2019 but the actual deadline will be different if the U.S. exchange offer is extended.

ii

Table of Contents

QUESTIONS AND ANSWERS ABOUT THE PROPOSED EXCHANGE OFFERS

        The summary term sheet in question and answer format set forth below highlights selected information about the exchange offers that is included elsewhere in this offer to exchange/prospectus. It does not, however, contain all of the information included in, or incorporated by reference into, this offer to exchange/prospectus and the related letter of transmittal or form of acceptance and you should read and consider all such information carefully before deciding whether or not to tender your Santander Mexico shares (as defined below) or Santander Mexico ADSs (as defined below) into the exchange offers.

Q.

What is Santander Spain proposing to do?

A.

Banco Santander, S.A., a company organized under the laws of the Kingdom of Spain (which we refer to as "Santander Spain") is proposing concurrent separate exchange offers to acquire all the issued and outstanding (i) Series B shares (which we refer to as "Santander Mexico shares") of Banco Santander México, S.A., Institución de Banca Múltiple, Grupo Financiero Santander México (which we refer to as "Santander Mexico") and (ii) in the U.S. exchange offer only, American Depositary Shares (each of which represents five Series B Santander Mexico shares and which we refer to as "Santander Mexico ADSs," and together with the Santander Mexico shares, the "Santander Mexico Securities"), in each case other than any Santander Mexico ADSs or Santander Mexico shares owned directly or indirectly by Santander Spain, in exchange for 0.337 of an ordinary share, nominal value €0.50 per share ("Santander Spain ordinary shares"), of Santander Spain for each Santander Mexico share and 1.685 Santander Spain American Depositary Shares (each of which represents one Santander Spain ordinary share and which we refer to as "Santander Spain ADSs") for each Santander Mexico ADS.

As of June 30, 2019, Santander Spain and its affiliates owned approximately 75% of Santander Mexico's total capital, consisting of 3,464,309,145 Series F shares (or 100% of the total outstanding Series F shares) and 1,629,163,910 Series B shares (or 49% of the total outstanding Series B shares.

Q.

Why is Santander Spain making these exchange offers?

A.

As explained in the section "Santander Spain's Reasons for the Proposed Exchange Offers," Santander Spain is making these exchange offers because it has confidence in the long-term growth potential of Santander Mexico and believes it will increase the weight of markets with structural growth in Santander Spain's business portfolio. In addition, Santander Spain believes that the proposed exchange offers are financially attractive for the shareholders of both Santander Spain and Santander Mexico.

Q.

How will the exchange offers be implemented?

A.

Santander Spain will implement the exchange offers as described below:

Santander Spain is conducting an exchange offer (the "U.S. exchange offer") pursuant to which it will deliver Santander Spain ordinary shares to holders of Santander Mexico shares and Santander Spain ADSs to holders of Santander Mexico ADSs, in each case that are tendered into, and not withdrawn from, the U.S. exchange offer through The Bank of New York Mellon (which we refer to as "BNY Mellon"), acting as the U.S. exchange agent for the U.S. exchange offer (which we refer to as the "U.S. exchange agent"). The U.S. exchange offer is available to all holders of Santander Mexico ADSs and to U.S. holders of Santander Mexico shares.

Santander Spain is conducting a concurrent separate exchange offer (the "Mexican exchange offer" and together with the U.S. exchange offer, the "exchange offers") pursuant to which it will deliver Santander Spain ordinary shares to holders of Santander Mexico shares tendered into, and not

1

Table of Contents

withdrawn from, the Mexican exchange offer. The Mexican exchange offer is available to all holders of Santander Mexico shares (whether U.S. holders or non-U.S. holders).

We refer to the Santander Spain ordinary shares and Santander Spain ADSs collectively in this offer to exchange/prospectus as the "Santander Spain Securities."

Q.

Has Santander Mexico or its board of directors made any recommendation regarding the exchange offers?

A.

Santander Mexico is a Mexican company and Mexican law governs the duties and obligations of Santander Mexico's board of directors. As of the date of this offer to exchange/prospectus, Santander Mexico's board of directors has not made any recommendation to its shareholders in connection with the exchange offers. However, under Mexican law, within ten business days after the commencement of the Mexican exchange offer, the board of directors of Santander Mexico is required to prepare and disclose (i) an opinion on the price of the Mexican exchange offer, (ii) any conflicts of interests which each of the board members may have in connection with the Mexican exchange offer, and (iii) if each member will tender his or her Santander Mexico ordinary shares as part of the Mexican exchange offer. The opinion of the board of directors of Santander Mexico, described in (i) above, may be accompanied by the opinion of a financial advisor. In addition, under U.S. law, within ten business days after the commencement of the U.S. exchange offer, Santander Mexico is required to file with the SEC and distribute to its shareholders a statement indicating whether it recommends in favor of the U.S. exchange offer, recommends against the U.S. exchange offer, expresses no position and remains neutral in connection with the U.S. exchange offer or expresses that it is unable to take a position regarding the U.S. exchange offer. In each case the board is required to explain the reasons for its position.

Q.

Can I tender my Santander Mexico shares and/or my Santander Mexico ADSs into the U.S. exchange offer?

A.

If you are a holder of Santander Mexico ADSs or are a U.S. holder of Santander Mexico shares, you can tender them into the U.S. exchange offer, and you will receive Santander Spain ordinary shares or Santander Spain ADSs, as applicable. If you are a non-U.S. holder of Santander Mexico shares, you cannot tender into the U.S. exchange offer and will instead need to tender into the Mexican exchange offer and receive Santander Spain ordinary shares.

Q.

Can I tender my Santander Mexico ADSs into the Mexican exchange offer?

A.

No. Holders of Santander Mexico ADSs may only tender their Santander Mexico ADSs in the U.S. exchange offer through the U.S. exchange agent and are not eligible to directly tender their Santander Mexico ADSs into the Mexican exchange offer.

Q.

What will I receive if the exchange offers are completed?

A.

If the exchange offers are completed, you will receive 0.337 of a Santander Spain ordinary share for each Santander Mexico share and 1.685 Santander Spain ADSs for each Santander Mexico ADS you tender into, and do not withdraw from, the U.S. exchange offer. The treatment of fractional shares is described in the following question.

Q.

Will I receive fractional Santander Spain Securities?

A.

No fractional Santander Spain Securities will be issued to you in connection with the exchange offers.

2

Table of Contents

Instead of any such fractional Santander Spain Securities that you would otherwise be entitled to receive in the U.S. exchange offer, the U.S. exchange agent will aggregate all fractional Santander Spain ordinary shares or Santander Spain ADSs (or the underlying Santander Spain ordinary shares) that all tendering holders tendering through the U.S. exchange agent would otherwise be entitled to receive pursuant to the U.S. exchange offer, sell such fractional Santander Spain ordinary shares or Santander Spain ADSs (or the underlying Santander Spain ordinary shares) at such times, in such manner and on such terms as the U.S. exchange agent determines in its reasonable discretion and pay the resulting net cash proceeds in U.S. dollars to such tendering holders.

Q.

If I tender my Santander Mexico shares and/or my Santander Mexico ADSs into the exchange offers, what upcoming dividends of Santander Mexico and Santander Spain will I receive?

A.

Santander Spain will declare the first interim dividend to be paid against its 2019 results with a record date yet to be determined. Santander Spain expects that settlement of the exchange offers will occur prior to that record date such that holders of Santander Mexico Securities that tender into the exchange offers will receive the first interim dividend. In the event that the settlement of the exchange offers occurs after the aforementioned record date, Santander Spain will amend the exchange ratio in the exchange offers to provide for a positive adjustment for tendering holders of Santander Mexico Securities to reflect the value of the first interim dividend and any subsequent Santander Spain dividends not paid to them. In the event that Santander Mexico pays any dividend after the May 28, 2019 dividend with a record date prior to the settlement of the exchange offers, Santander Spain will amend the exchange ratio to provide for a negative adjustment for tendering holders of Santander Mexico Securities to reflect the value of such Santander Mexico dividend. In the case of any amendment to the exchange ratio, Santander Spain will announce the new exchange ratio and, if required pursuant to SEC or Mexican rules, extend the expiration date for both exchange offers.

Q.

How do I tender my Santander Mexico shares or Santander Mexico ADSs in the U.S. exchange offer?

A.

The steps you must take to tender into the U.S. exchange offer will depend on whether you hold Santander Mexico shares or Santander Mexico ADSs and whether you hold such Santander Mexico shares or Santander Mexico ADSs directly or indirectly through a broker or other securities intermediary.

•

If you hold Santander Mexico ADSs and would like to tender them into the U.S. exchange offer, you must tender them to the U.S. exchange agent prior to the expiration time, which is 1:00 p.m. Eastern time (12:00 p.m. Mexico City time) on the expiration date. The expiration date is currently                , 2019, but this date will change if the exchange offers are extended. In order to tender your Santander Mexico ADSs, you must take the following actions:

•

If you hold your Santander Mexico ADSs directly evidenced by Santander Mexico ADRs, you must complete and sign the letter of transmittal included with this offer to exchange/prospectus and return it together with your Santander Mexico ADRs and any required documentation to the U.S. exchange agent at the appropriate address specified on the letter of transmittal.

•

If you hold your Santander Mexico ADSs directly in uncertificated form on the books of the Santander Mexico ADS depositary, in order to tender your Santander Mexico ADSs you must complete and sign the letter of transmittal included with this offer to exchange/prospectus and return it together with any required documentation to the U.S. exchange agent at the appropriate address specified on the letter of transmittal.

3

Table of Contents

•

If you hold your Santander Mexico ADSs indirectly through a broker or other securities intermediary, you must instruct your broker or other securities intermediary to tender your Santander Mexico ADSs to the U.S. exchange agent on your behalf (i) if such Santander Mexico ADSs are evidenced by Santander Mexico ADRs, in the form of Santander Mexico ADRs, together with a duly executed and properly completed letter of transmittal and any other required documentation, or (ii) if such Santander Mexico ADSs are held in book-entry form by your broker or other securities intermediary, by book-entry transfer to a designated account at The Depository Trust Company (which we refer to as "DTC") by using DTC's automated tender system.



•

If you hold Santander Mexico shares and would like to tender them into the U.S. exchange offer, you must tender them to the U.S. exchange agent prior to the expiration time, which is 1:00 p.m. Eastern time (12:00 p.m. Mexico City time) on the expiration date. The expiration date is currently                , 2019, but this date will change if the exchange offers are extended. In order to tender your Santander Mexico shares, you must take the following actions:



•

If you hold Santander Mexico shares directly in book-entry form on the books and records of S.D. Indeval Institución para el Depósito de Valores, S.A. de C.V. ("Indeval"), in order to tender your Santander Mexico shares you must do so by book-entry transfer as described below. You will not be able to tender into the U.S. exchange offer any Santander Mexico shares in certificated form. If you hold Santander Mexico shares in certificated form you should promptly contact any broker or other securities intermediary who is a participant in the book-entry transfer system of Indeval and arrange for such a nominee to hold the Santander Mexico shares on your behalf in book-entry form. You may have to pay fees and charges in connection with this process. In order to effect a tender of the Santander Mexico shares you own directly or beneficially, you should promptly contact your broker or other Mexican securities intermediary and instruct it to tender such Santander Mexico shares.



•

If you hold your Santander Mexico shares through a broker, or other Mexican securities intermediary who is not an Indeval participant, such nominee, on your behalf, should promptly contact an Indeval participant and make arrangements for the tender of the Santander Mexico shares into the Indeval account of Banco S3 Mexico; Account number: 02 101 9913 for the account of BNY Mellon, as the U.S. exchange agent, in accordance with the procedures of Indeval on or prior to the expiration of the U.S. exchange offer.



•

A valid tender will be deemed to have been received only if (i) the U.S. exchange agent receives a confirmation from Banco S3 Mexico, as the custodian, of a book-entry transfer before expiration of the U.S. exchange offer of the Santander Mexico shares into the Indeval account at 02 101 9913 for the account of the U.S. exchange agent and (ii) the U.S. exchange agent has received from the Indeval participant through which such Santander Mexico shares were tendered before the expiration of the U.S. exchange offer a duly completed and executed U.S. Form of Acceptance. The book-entry transfer confirmation and executed U.S. Form of Acceptance must be received by the U.S. exchange agent in accordance with the terms and conditions of the U.S. exchange offer by 1:00 p.m. Eastern time (12:00 p.m. Mexico City time) on the expiration date.

Any Santander Mexico ADSs or Santander Mexico shares being tendered must be delivered in accordance with the procedures described in this offer to exchange/prospectus on or before the expiration of the U.S. exchange offer. There will be no guaranteed delivery procedures permitting delivery of the Santander Mexico shares or Santander Mexico ADSs after the expiration. For more information on the procedure for tendering, the time and expense of tendering, the timing of the exchange offers, extensions of the exchange offers and your rights to withdraw your Santander Mexico shares and/or Santander Mexico ADSs from the exchange offers prior to the expiration

4

Table of Contents

time, see "The Exchange Offers" section of this offer to exchange/prospectus beginning on page 60.

Q.

Will I have to pay any fees or commissions for tendering my Santander Mexico shares or Santander Mexico ADSs?

A.

If your Santander Mexico shares or Santander Mexico ADSs are tendered into the exchange offers by your broker or other securities intermediary, you will be responsible for any fees or commissions they may charge you in connection with such tender. In addition, you will be responsible for all governmental charges and taxes payable in connection with tendering your Santander Mexico shares and/or Santander Mexico ADSs. You will not have to pay any fee to the U.S. exchange agent for tendering your Santander Mexico shares and/or Santander Mexico ADSs through the U.S. exchange agent, nor to Casa de Bolsa Santander, S.A. de C.V. Grupo Financiero Santander México, as broker-dealer.

Q.

How much time do I have to decide whether to tender?

A.

If you hold Santander Mexico ADSs, you may tender your Santander Mexico ADSs into the U.S. exchange offer through the U.S. exchange agent at any time prior to the expiration time, which is 1:00 p.m. Eastern time (12:00 p.m. Mexico City time), on the expiration date (which is currently                , 2019 but will change if the exchange offers are extended). If you hold Santander Mexico shares and would like to tender them into the U.S. exchange offer, you should follow the procedures described in "The Exchange Offers—Procedure for Tendering" section under "—Holders of Santander Mexico Shares". Brokers and other securities intermediaries will set their own cut-off dates and times to receive instructions to tender Santander Mexico Securities that will be earlier than the expiration date and time specified in this offer to exchange/prospectus. You should contact your broker or other securities intermediary to determine the cut-off date and time that applies to you. For more information on the time involved in tendering your Santander Mexico shares and/or Santander Mexico ADSs in the exchange offers, see "The Exchange Offers—Procedure for Tendering" section of this offer to exchange/prospectus beginning on page 65.

Q.

Can the exchange offers be extended?

A.

Yes. Subject to applicable rules and regulations in the United States and Spain and, with respect to the Mexican exchange offer, approval of the CNBV in Mexico, Santander Spain may extend the exchange offers. Santander Spain will announce any extension of the exchange offers by issuing a press release no later than 8:00 a.m. Eastern time (7:00 a.m. Mexico City time), on the next business day following the expiration date on, among others, the Dow Jones News Service. In addition, Santander Spain will post a notice of any extension on the website www.santander.com, and through the MSE's Electronic Communication System with Securities Issuers (Sistema Electrónico de Comunicación con Emisoras de Valores, or Emisnet), through the website www.bmv.com.mx, as well as through the CNBV's Securities Information Transfer System (Sistema de Transferencia de Información de Valores, or STIV), through the website www.gob.mx/cnbv. The information on Santander Spain's website is not a part of this offer to exchange/prospectus and is not incorporated by reference herein.

Q.

Can I withdraw Santander Mexico shares or Santander Mexico ADSs that I have tendered?

A.

You may withdraw any Santander Mexico shares and Santander Mexico ADSs tendered into the U.S. exchange offer through the U.S. exchange agent at any time prior to the expiration time. If you tender your Santander Mexico shares into the Mexican exchange offer, you may withdraw such Santander Mexico shares at any time prior to 1:00 p.m. Eastern time (12:00 p.m. Mexico City time) on the expiration date. In addition, in accordance with U.S. securities laws, you may

5

Table of Contents

withdraw your tendered Santander Mexico shares or Santander Mexico ADSs if they have not been accepted for exchange by                        (60 days after the date of this offer to exchange/prospectus). Brokers and other securities intermediaries will set their own cut-off dates and times to receive instructions to withdraw Santander Mexico Securities that will be earlier than the expiration date and time specified in this offer to exchange/prospectus. You should contact your broker or other securities intermediary to determine the cut-off date and time that applies to you.

Q.

What are the most significant conditions to the exchange offers?

A.

The exchange offers are subject to the conditions set forth in "The Exchange Offers—Conditions to Completion of the Exchange Offers" section of this offer to exchange/prospectus beginning on page 63, including that all governmental approvals and authorizations required in connection with the exchange offers shall have been obtained and shall have not been revoked or amended, modified or supplemented in any way that could reasonably be expected to materially impede or interfere with, delay, postpone or materially and adversely affect the completion of the exchange offers, the absence of any governmental, judicial, legislative or regulatory developments that would adversely impact the ability to consummate the exchange offers, the absence of any material adverse change (or any condition, event or development involving a prospective change) in the business, properties, assets, liabilities, capitalization, shareholders' equity, condition (financial or otherwise), operations, licenses, franchises, permits, permit applications, results of operations, cash flows or prospects of Santander Mexico or any of its subsidiaries, and the satisfaction of other customary conditions.

Q.

Will tendered shares be subject to proration?

A.

No. Subject to the terms and conditions of the exchange offers, Santander Spain will acquire any and all Santander Mexico shares and Santander Mexico ADSs validly tendered into, and not withdrawn from, the exchange offers.

Q.

Do I need to do anything if I want to retain my Santander Mexico shares or Santander Mexico ADSs?

A.

No. If you want to retain your Santander Mexico shares or Santander Mexico ADSs, you do not need to take any action.

Q.

If I do not participate in the exchange offers, will my Santander Mexico Securities continue to be listed on the New York Stock Exchange and the MSE?

A.

NYSE.    The NYSE has certain listing standards which, if not satisfied, may require delisting. According to the NYSE's published guidelines, the NYSE would consider delisting the Santander Mexico ADSs if, among other things, (i) the total number of holders of Santander Mexico ADSs falls below 400, (ii) the total number of holders of Santander Mexico ADSs falls below 1,200 and the average monthly trading volume for Santander Mexico ADSs is less than 100,000 for the most recent 12 months or (iii) the number of publicly held Santander Mexico ADSs (exclusive of holdings of officers and directors of Santander Mexico and their immediate families and other concentrated holdings of 10% or more) falls below 600,000. We have been informed by Santander Mexico that as of June 27, 2019, there were 6,208 beneficial holders of 150,801,462 Santander Mexico ADSs, all of which we believe were publicly held under the NYSE definition. Therefore, as of that date, the NYSE would consider delisting the Santander Mexico ADSs if (i) at least 93.57% of holders tendered all of their Santander Mexico ADSs into the U.S. exchange offer, (ii) at least 80.68% of holders tendered all of their Santander Mexico ADSs into the U.S. exchange offer and the average monthly trading volume for Santander Mexico ADSs fell below 100,000 shares for the previous 12 months or (iii) at least 99.61% of publicly held Santander Mexico ADSs were tendered

6

Table of Contents

into the U.S. exchange offer. Although we currently do not intend to request delisting of the Santander Mexico ADS, even if the listing standards continue to be satisfied, we may request the delisting at some time in the future. Absent delisting, Santander Mexico ADSs will continue to be traded subsequent to the U.S. exchange offer, but liquidity may be negatively affected.

MSE—Voluntary Deregistration and Delisting in Mexico.    Santander Mexico shares will continue to trade on the MSE unless the CNBV authorizes the cancellation of the registration of the Santander Mexico shares in the National Securities Registry of the CNBV ("deregistration"). The Mexican Securities Market Law provides that the CNBV shall authorize deregistration and delisting if the interests of minority shareholders and the market in general have been adequately protected. Additionally, under Mexican law, among other conditions, we would be required to obtain approval of the holders of at least 95% of the outstanding Santander Mexico shares, including any Santander Mexico shares we acquire in the exchange offers, voting at a shareholders meeting to approve resolutions permitting deregistration and delisting. If we do not reach the 95% ownership level immediately following consummation of the exchange offers, we may pursue other transactions in the future that would increase our direct and indirect ownership to that level. We do not have any current intention to engage in any such transactions or to cause the deregistration or delisting of Santander Mexico shares.

MSE—Mandatory Deregistration and Delisting in Mexico.    If Santander Mexico ceases to comply with (i) having the minimum number of investors as required by the MSE internal regulations, (ii) having 12% or more of the paid-in capital stock among the investing public, and (iii) other listing requirements pursuant to the regulations of the MSE (the "Listing Requirements"), the CNBV may (a) determine the cancellation of the registration of the shares of Santander Mexico in the National Registry of Securities (Registro Nacional de Valores) ("RNV"), as well as their elimination from the list of securities authorized to be listed on the MSE, and (b) Santander Spain may be required by the CNBV to make an additional offer for Santander Mexico shares, within the following 180 calendar days from the CNBV request. The consideration offered by Santander Spain as part of any such additional offer under applicable Mexican law would be the greater of the average trading price of the Santander Mexico shares for the 30 days prior to such subsequent offer and their book value. We may be able to offer a different price in any such additional offer, subject to prior approval from the CNBV, based upon, amongst other factors, Santander Mexico's financial condition and prospects at the time and after approval of such price by Santander Mexico's board of directors, taking into consideration the opinion of its Audit and Corporate Practices Committee in accordance with Mexican law. Any such consideration may be different than that offered in the exchange offers. In such scenario, the Mexican Securities Market Law provides that the CNBV may determine the deregistration and delisting of Santander Mexico, if the interests of minority shareholders and the market in general have been adequately protected.

In the event of the deregistration and delisting of the Santander Mexico shares, the CNBV may require, in accordance with applicable provisions of the Mexican Securities Market Law, for Santander Spain to incorporate a repurchase trust (fideicomiso) holding resources sufficient to purchase any Santander Mexico shares that remain outstanding following completion of the exchange offers at a price equal to the greater of (i) the market value of Santander Mexico's outstanding shares, or (ii) the book value of Santander Mexico's outstanding shares. The repurchase trust would offer to purchase Santander Mexico shares for a period of at least six months from the date that the registry of the Santander Mexico shares is canceled.

The circumstances that would lead to the incorporation of the repurchase trust, or to our making an additional offer for Santander Mexico shares, may not arise or may occur only after significant delays. There can accordingly be no assurance that there will be a repurchase trust or that we will make an additional offer or as to the timing of any repurchase trust or any such additional offer.

7

Table of Contents

After completion of the exchange offers, Santander Spain or Santander Mexico may also acquire Santander Mexico shares, including by means of open market purchases or privately negotiated purchases.

Q.

Will there be any additional offers made by Santander Spain for the Santander Mexico shares or Santander Mexico ADSs?

A.

In the event of the deregistration and delisting of the Santander Mexico shares, the CNBV may require, in accordance with applicable provisions of the Mexican Securities Market Law, that Santander Spain incorporate a repurchase trust (fideicomiso) holding resources sufficient to purchase any Santander Mexico shares that remain outstanding following completion of the exchange offers. The repurchase trust would offer to purchase Santander Mexico shares for a period of at least six months from the date that the registry of the Santander Mexico shares is canceled.

If Santander Mexico ceases to comply with the Listing Requirements, (a) the CNBV may determine the cancellation of the registration of the shares of Santander Mexico in the RNV, as well as their elimination from the list of securities authorized to be listed on the MSE, and (b) Santander Spain may be required by the CNBV to make an additional offer for Santander Mexico shares, within the following 180 calendar days from the CNBV request. The consideration offered by Santander Spain as part of any such additional offer under applicable Mexican law would be the greater of the average trading price of the Santander Mexico shares for the 30 days prior to such subsequent offer and their book value. We may be able to offer a different price in any such additional offer, subject to prior approval from the CNBV, based upon, amongst other factors, Santander Mexico's financial condition and prospects at the time and after approval of such price by Santander Mexico's board of directors, taking into consideration the opinion of its Audit and Corporate Practices Committee in accordance with Mexican law. Any such consideration may be different than that offered in the exchange offers.

The circumstances that would lead to the incorporation of the repurchase trust, or to our making an additional offer for Santander Mexico shares, may not arise or may occur only after significant delays. There can accordingly be no assurance that there will be a repurchase trust or that we will make an additional offer or as to the timing of any repurchase trust or any such additional offer.

After completion of the exchange offers, Santander Spain or Santander Mexico may also acquire Santander Mexico shares or Santander Mexico ADSs, including by means of open market purchases or privately negotiated purchases.

Q.

Will I have appraisal rights in connection with the exchange offers?

A.

No. There are no appraisal or similar rights available to holders of Santander Mexico shares or Santander Mexico ADSs in connection with the exchange offers. For more information about appraisal rights of holders of Santander Mexico shares and Santander Mexico ADSs, see "The Exchange Offers—Appraisal Rights" section of this offer to exchange/prospectus beginning on page 88.

Q.

Can Santander Spain squeeze out the holders of Santander Mexico shares and Santander Mexico ADSs that do not tender into the exchange offers?

A.

No. Under Mexican law, corporations, such as Santander Spain, are not entitled to conduct a squeeze out of or compulsorily redeem the Santander Mexico shares or Santander Mexico ADSs not tendered into the exchange offers.

8

Table of Contents

Q.

How and where will the outcome of the exchange offers be announced?

A.

Santander Spain will announce the outcome of the exchange offers by issuing a press release no later than 8:00 a.m. Eastern time (7:00 a.m. Mexico City time) on the first business day after the expiration date on, among others, the Dow Jones News Service and through the MSE. In addition, Santander Spain will post a notice of the results of the exchange offers on www.santander.com. The information on www.santander.com is not a part of this offer to exchange/prospectus and is not incorporated by reference herein.

Q.

When are the exchange offers expected to be completed?

A.

Santander Spain expects to complete the exchange offers in the second half of 2019.

Q.

What are the tax consequences if I participate in the exchange offers?

A.

For more information on the Spanish, Mexican and U.S. tax consequences of the exchange offers, see "The Exchange Offers—Tax Consequences" section of this offer to exchange/prospectus beginning on page 75. Additionally, for certain Mexican tax consequences of your participation in the exchange offers that are uncertain, see the "Risk Factors—You will need to consider the Mexican tax consequences of the transaction and of holding Santander Spain Securities" section of this offer to exchange/prospectus beginning on page 29, and for certain Spanish tax consequences of your participation in the exchange offers that are uncertain, see the "Risk Factors—You will need to consider the Spanish tax consequences of the transaction and of holding Santander Spain Securities" section of this offer to exchange/prospectus beginning on page 29. You should consult your own tax advisor on the tax consequences to you of tendering your Santander Mexico shares and/or Santander Mexico ADSs in the exchange offers. If you are not located in the United States or are not a U.S. person (as such terms are defined in Regulation S under the Securities Act), you should consult the separate offering documents relating to the exchange offers that are being published in Mexico and made available to all holders of Santander Mexico shares.

Q.

Is Santander Spain's financial condition relevant to my decision to tender my Santander Mexico Securities into the exchange offers?

A.

Yes. If the exchange offers are consummated and if you so elect, you will receive Santander Spain ordinary shares or Santander Spain ADSs as consideration in the exchange offers and you should consider our financial condition before you decide to become one of our shareholders through the exchange offers. In considering our financial condition, you should also review the documents incorporated by reference in this offer to exchange/prospectus because they contain detailed business, financial and other information about us.

Q.

If my Santander Mexico shares or Santander Mexico ADSs are acquired in the exchange offers, how will my rights as a Santander Mexico shareholder or as a holder of Santander Mexico ADSs change?

A.

If your Santander Mexico shares or Santander Mexico ADSs are acquired in the exchange offers, you will become a holder of Santander Spain ordinary shares or Santander Spain ADSs, which will represent one Santander Spain ordinary share deposited with the applicable depositary. Your rights as a holder of Santander Spain ADSs will be determined by the deposit agreement among Santander Spain, the Santander Spain ADS depositary and the holders from time to time of the Santander Spain ADSs issued thereunder (which we refer to as the "Santander Spain ADS deposit agreement"). The rights of a holder of the Santander Spain ordinary shares (including Santander Spain ordinary shares represented by your Santander Spain ADSs) will be governed by Santander Spain's by-laws, the Spanish corporation law (Texto Refundido de la Ley de Sociedades de Capital

9

Table of Contents

aprobado por el Real Decreto Legislativo 1/2010), as amended (which we refer to as "Spanish Corporation Law"), and the Spanish corporation regulations. For a summary of the material differences between the rights of holders of Santander Spain ordinary shares compared to the rights of holders of Santander Mexico shares, see the "Comparison of Rights of Holders of Santander Spain Securities and Santander Mexico Securities" section of this offer to exchange/prospectus beginning on page 110. For a summary of the material differences between the rights of holders of Santander Spain ADSs compared to the rights of holders of Santander Mexico ADSs, see the "Comparison of Rights of Holders of Santander Spain Securities and Santander Mexico Securities" section of this offer to exchange/prospectus beginning on page 110.

Q.

When will I receive my Santander Spain ordinary shares or Santander Spain ADSs?

A.

Under Spanish law, a number of procedural steps must be taken after the exchange offers are completed and before the Santander Spain ADSs and/or Santander Spain ordinary shares can be delivered. If the exchange offers are completed, we expect that you will receive the Santander Spain ADSs you are entitled to receive pursuant to the exchange offers on or about the sixth U.S. business day following the expiration date and the Santander Spain ordinary shares you are entitled to receive pursuant to the exchange offers on or about the sixth Mexican business day following the expiration date. It is expected that the payment of cash in lieu of fractional Santander Spain ADSs and/or Santander Spain ordinary shares will be made with or promptly following delivery of the Santander Spain ADSs and/or Santander Spain ordinary shares

Q.

What if the exchange offers are not consummated or Santander Mexico shares or Santander Mexico ADSs that I have tendered into the exchange offers are not accepted for any reason?

A.

If the exchange offers are not consummated or any Santander Mexico shares or Santander Mexico ADSs that have been tendered into the exchange offers are not accepted for any reason, the Santander Mexico shares and Santander Mexico ADSs so tendered will be returned to the tendering shareholders and holders of ADSs by the U.S. exchange agent as soon as practicable after the expiration or termination of the U.S. exchange offer.

Q.

Can I tender less than all the Santander Mexico shares or Santander Mexico ADSs that I own into the exchange offers?

A.

Yes. You may elect to tender all or a portion of the Santander Mexico shares or Santander Mexico ADSs that you own into the exchange offers.

Q.

Who can I call with questions?

A.

If you have more questions about the exchange offers, you should contact Morrow Sodali at 509 Madison Avenue, Suite 1206, New York, NY 10022, by telephone at (800) 662-5200 or email at Santander@morrowsodali.com.

10

Table of Contents

WHERE YOU CAN FIND MORE INFORMATION

        Each of Santander Spain and Santander Mexico files with, and furnishes to, the SEC reports and other information. You may obtain copies of these reports and other information from the SEC at www.sec.gov. You may also inspect certain reports and other information concerning Santander Spain and Santander Mexico at the offices of the New York Stock Exchange (which we refer to as the "NYSE") located at 20 Broad Street, New York, New York 10005.

        Santander Spain makes available free of charge through its website accessible at www.santander.com certain of Santander Spain's reports and other information filed with or furnished to the SEC. With the exception of the reports specifically incorporated by reference in this document as set forth in "Incorporation of Certain Information By Reference," material contained on or accessible through Santander's website is not incorporated into this document. You may also request a copy of Santander Spain's filings at no cost, by writing or calling Santander Spain at the following address:

Banco Santander, S.A.
New York Branch
45 East 53^rd Street
New York, New York 10022
Attention: Investor Relations
Telephone: (212) 350-3681

or

Banco Santander, S.A.
Ciudad Grupo Santander
Avenida de Cantabria, s/n
Edificio Pereda, 2a planta
28660 Boadilla del Monte
Madrid, Spain
Attention: Investor Relations
Telephone: (011) 34-91-259-6520

or

Banco Santander México, S.A., Institución de Banca Múltiple, Grupo Financiero Santander México
Avenida Prolongación Paseo de la Reforma 500
Colonia Lomas de Santa Fe
Delegación Álvaro Obregón
01219 Mexico City
Attention: Shareholders Relations
Telephone: (+52) 55-5257-8000
Fax: (+52) 55-5269-2701

        Santander Spain has filed with the SEC a registration statement on Form F-4 (which we refer to as the "Registration Statement") to register under the Securities Act the offer and sale of Santander Spain ordinary shares pursuant to the U.S. exchange offer to holders of Santander Mexico ADSs and holders of Santander Mexico shares to be tendered into the U.S. exchange offer through the U.S. exchange agent. This offer to exchange/prospectus forms a part of that Registration Statement. Santander Spain has also filed with the SEC a statement on Schedule TO pursuant to Rule 14d-3 under the Exchange Act furnishing certain information with respect to the exchange offer. In addition, BNY Mellon as the Santander Spain ADS depositary, has filed a registration statement on Form F-6, to register with the SEC the Santander Spain ADSs to be issued in connection with the U.S. exchange

11

Table of Contents

offer. The Registration Statement, the Schedule TO and the Form F-6 and any amendments thereto will be available for inspection and copying as set forth above.

        DOCUMENTS INCORPORATED BY REFERENCE ARE ALSO AVAILABLE FROM SANTANDER SPAIN WITHOUT CHARGE UPON REQUEST TO MORROW SODALI, AT 509 MADISON AVENUE, SUITE 1206, NEW YORK, NY 10022, ONLINE AT WWW.MORROWSODALI.COM, EMAIL AT SANTANDER@MORROWSODALI.COM, COLLECT AT (203) 658-9400 OR TOLL-FREE AT (800) 662-5200. IN ORDER TO ENSURE TIMELY DELIVERY OF ANY OF THESE DOCUMENTS, ANY REQUEST SHOULD BE SUBMITTED NO LATER THAN FIVE BUSINESS DAYS PRIOR TO THE THEN-SCHEDULED EXPIRATION DATE OF THE EXCHANGE OFFERS. THIS DEADLINE IS CURRENTLY                , 2019 BECAUSE THE EXPIRATION DATE OF THE EXCHANGE OFFERS IS CURRENTLY                , 2019 BUT THE ACTUAL DEADLINE WILL BE DIFFERENT IF THE EXCHANGE OFFERS ARE EXTENDED. IF YOU REQUEST ANY INCORPORATED DOCUMENTS FROM SANTANDER SPAIN, SANTANDER SPAIN WILL MAIL THEM TO YOU BY FIRST CLASS MAIL, OR OTHER EQUALLY PROMPT MEANS, WITHIN ONE BUSINESS DAY AFTER SANTANDER SPAIN RECEIVES YOUR REQUEST.

        Santander Spain has not authorized anyone to give any information or make any representation about the exchange offers that is different from, or in addition to, the information contained in this offer to exchange/prospectus or in any materials incorporated by reference into this offer to exchange/prospectus. The information contained in this offer to exchange/prospectus speaks only as of the date of this offer to exchange/prospectus unless the information specifically indicates that another date applies.

12

Table of Contents

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

        As allowed by the SEC, this offer to exchange/prospectus does not contain all of the information that is deemed to be included in this offer to exchange/prospectus. This is because the SEC allows Santander Spain to "incorporate by reference" into this offer to exchange/prospectus certain reports and other documents that Santander Spain and Santander Mexico file with, or furnish to, the SEC both before and after the date of this offer to exchange/prospectus. The reports and other documents incorporated by reference into this offer to exchange/prospectus contain important information concerning Santander Spain and Santander Mexico and the information contained in those reports and other documents incorporated by reference herein (except to the extent superseded by information expressly contained herein) is deemed to form part of this offer to exchange/prospectus even though such information is not physically included herein.

        This offer to exchange/prospectus incorporates by reference the following documents filed with, or furnished to, the SEC by Santander Spain or Santander Mexico prior to the date of this offer to exchange/prospectus:

•

Santander Spain's Annual Report on Form 20-F for the fiscal year ended December 31, 2018, filed on March 26, 2019 (which we refer to as the "Santander Spain 2018 Form 20-F");



•

Santander Spain's Current Report on Form 6-K, filed on July 8, 2019 relating to certain recast financial information as a result of certain changes in the geographic and business segments of Santander Spain (which we refer to as the "Santander Spain 6-K with Recast 20-F");



•

Unaudited Interim Condensed Consolidated Financial Statements as of, and for the three-month period ended March 31, 2019, and Director's Report relating to the first quarter of 2019, included in Santander Spain's Current Report on Form 6-K for the month of May, 2019, filed on May 14, 2019;



•

Unaudited Interim Condensed Consolidated Financial Statements as of, and for the six-month period ended June 30, 2019, and Director's Report and Supplemental Information relating to the second quarter of 2019, included in Santander Spain's Current Report on Form 6-K for the month of August, 2019, filed on August 1, 2019 (which we refer to as the "Santander Spain Second Quarter Results Form 6-K");



•

The description of the Santander Spain ADSs under the heading "Description of American Depositary Shares" in Santander Spain's registration statement under the Securities Act on Form F-3, filed on June 22, 2017 (which we refer to as the "Santander Spain 2017 Form F-3");



•

Santander Mexico's Annual Report on Form 20-F for the fiscal year ended December 31, 2018, filed on April 30, 2019 (which we refer to as the "Santander Mexico 2018 Form 20-F");



•

Unaudited Interim Condensed Consolidated Financial Statements as of, and for the three-month period ended March 31, 2019, prepared under Mexican Banking Generally Accepted Accounting Principles (GAAP) (the accounting standards of the CNBV) with reconciliation to International Financial Reporting Standards (which we refer to as "IFRS"), included in Santander Mexico's Current Report on Form 6-K for the month of May, 2019, filed on May 8, 2019;



•

Unaudited Interim Condensed Consolidated Financial Statements as of, and for the six-month period ended June 30, 2019, prepared under Mexican Banking GAAP with reconcilation to IFRS, included in Santander Mexico's Current Report on Form 6-K for the month of July, 2019, filed on July 26, 2019 (which we refer to as the "Santander Mexico Second Quarter Results Form 6-K");



•

The description of the Santander Mexico shares under the heading "The SanMex Shares and Articles of Association" in Santander Mexico's registration statement under the Securities Act on Form F-4, filed on October 30, 2017, and as amended on December 1, 2017 and

13

Table of Contents

December 7, 2017 (which we refer to as the "Santander Mexico 2017 Form F-4") and the description of the Santander Mexico ADSs under the heading "Description of Securities to be Registered" in Santander Mexico's registration statement under the Securities Act on Form F-6, filed on January 19, 2018 (which we refer to as the "Santander Mexico 2018 Form F-6").

        In addition, all annual reports on Form 20-F that Santander Spain and Santander Mexico file with the SEC and all reports on Form 6-K that Santander Spain and Santander Mexico furnish to the SEC indicating that they are so incorporated by reference into this offer to exchange/prospectus, in each case after the date of this offer to exchange/prospectus and prior to the expiration or termination of the exchange offer, will also be incorporated by reference into this offer to exchange/prospectus. Any information contained in, or incorporated by reference into, this offer to exchange/prospectus prior to the filing with, or furnishing to, the SEC of any such report after the date of this offer to exchange/prospectus shall be deemed to be modified or superseded to the extent that the disclosure in such report modifies or supersedes such information.

        Upon your request, Santander Spain's information agent will provide to you without charge copies of any or all reports and documents described above that are incorporated by reference into this offer to exchange/prospectus (other than exhibits to such documents, unless such exhibits are specifically incorporated by reference). Requests for such copies should be directed to Santander Spain's information agent, Morrow Sodali at 509 Madison Avenue, Suite 1206, New York, NY 10022. To obtain timely delivery of any of these documents, you must request them no later than five business days before the then-scheduled expiration date of the exchange offers. This deadline is currently            , 2019 because the expiration date of the exchange offers is currently            , 2019 but the actual deadline will be different if the exchange offers are extended.

        Santander Spain has provided only the information contained in, or incorporated by reference into, this offer to exchange/prospectus in deciding whether or not to accept the exchange offers. Santander Spain has not authorized anyone to provide you with any information that is different from what is contained in, or incorporated by reference into, this offer to exchange/prospectus. The information contained in, or incorporated by reference into, this offer to exchange/prospectus is accurate only as of its date. You should not assume that such information is accurate as of any other date and neither the mailing of this offer to exchange/prospectus to you nor the issuance of Santander Spain ADSs or Santander Spain ordinary shares in connection with the exchange offers shall create any implication to the contrary.

14

Table of Contents

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

        This offer to exchange/prospectus contains or incorporates by reference "forward-looking statements" regarding the intent, belief or current expectations of Santander Spain, Santander Mexico and their respective directors and officers about Santander Spain, Santander Mexico, their respective subsidiaries and their respective businesses. Generally, words such as "may," "will," "expect," "intend," "estimate," "anticipate," "believe," "plan," "seek," "continue" or similar expressions identify forward-looking statements.

        Forward-looking statements are statements that are not historical facts. Rather, they are based on current plans, estimates and projections and involve inherent known and unknown risks, uncertainties and other factors, many of which are outside Santander Spain's and Santander Mexico's control and difficult to predict, that may cause actual results or developments to differ materially from any future results or developments expressed by or implied from forward-looking statements. Therefore, you should not place undue reliance on them. These risks and uncertainties include in particular those described in the documents Santander Spain and Santander Mexico have filed with the SEC that are incorporated by reference into this offer to exchange/prospectus and the following:

Economic and Industry Conditions

•

general economic or industry conditions in Spain, the U.K., the U.S., other European countries, Brazil, Mexico, other Latin American countries and the other areas in which Santander Spain has significant business activities or investments;



•

exposure to various types of market risks, principally including interest rate risk, foreign exchange rate risk and equity price risk;



•

a worsening of the economic environment in Spain, the U.K., the U.S., other European countries, Brazil, Mexico, other Latin American countries, and increase of the volatility in the capital markets;



•

the effects of a decline in real estate prices, particularly in Brazil, Mexico, Spain and the U.K.;



•

the effects of results of U.K. political developments, including the U.K.'s potential exit from the European Union.;



•

monetary and interest rate policies of the European Central Bank and various central banks;



•

inflation or deflation;



•

the effects of non-linear market behavior that cannot be captured by linear statistical models, such as the VaR model Santander Spain uses;



•

changes in competition and pricing environments;



•

the inability to hedge some risks economically;



•

the adequacy of loss reserves;



•

acquisitions or restructurings of businesses that may not perform in accordance with Santander Spain's expectations;



•

changes in demographics, consumer spending, investment or saving habits;



•

potential losses associated with prepayment of our loan and investment portfolio, declines in the value of collateral securing our loan portfolio, and counterparty risk; and



•

changes in competition and pricing environments as a result of the progressive adoption of the internet for conducting financial services and/or other factors.

15

Table of Contents

Political and Governmental Factors

•

political stability in Spain, the U.K., other European countries, Latin America and the U.S.;



•

changes in Spanish, U.K., E.U., U.S., Latin American, or other jurisdictions' laws, regulations or taxes, including changes in regulatory capital and liquidity requirements, including as a result of the U.K. exiting the European Union; and



•

increased regulation in light of the global financial crisis.

Transaction and Commercial Factors

•

damage to Santander Spain's reputation;



•

Santander Spain's ability to integrate successfully its acquisitions and the challenges inherent in diverting management's focus and resources from other strategic opportunities and from operational matters while Santander Spain integrates these acquisitions; and



•

the outcome of Santander Spain's negotiations with business partners and governments.

Operating Factors

•

potential losses associated with an increase in the level of non-performance by counterparties to other types of financial instruments;



•

technical difficulties and/or failure to improve or upgrade Santander Spain's information technology;



•

changes in Santander Spain's ability to access liquidity and funding on acceptable terms, including as a result of changes in its credit spreads or a downgrade in its credit rating or those of its more significant subsidiaries;



•

Santander Spain's exposure to operational losses (e.g., failed internal or external processes, people and systems);



•

the occurrence of force majeure, such as natural disasters, that impact Santander Spain's operations or impair the asset quality of its loan portfolio;



•

the impact of changes in the composition of Santander Spain's balance sheet on future net interest income / (charges); and



•

potential losses associated with cyber-attacks.

        Santander Spain cautions that any forward-looking statements contained or incorporated by reference in this offer to exchange/prospectus are further qualified by the risk factors contained or incorporated by reference in this offer to exchange/prospectus that could cause actual results to differ materially from those in the forward-looking statements. Forward-looking statements speak only as of the date they were made and, except as required by Rule 14d-3(b) under the Exchange Act, Santander Spain does not undertake any obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. You should read carefully the risk factors described in the "Risk Factors" section of this offer to exchange/prospectus beginning on page 26.

16

Table of Contents

17

Table of Contents

18

Table of Contents

19

Table of Contents

20

Table of Contents

21

Table of Contents

22

Table of Contents

23

Table of Contents

24

Table of Contents

25

Table of Contents

RISK FACTORS

        In addition to the matters described under the "Cautionary Statement Regarding Forward-Looking Statements" section of this offer to exchange/prospectus beginning on page 15 and the risk factors contained in the Santander Spain 2018 Form 20-F and the Santander Mexico 2018 Form 20-F that are incorporated by reference into this offer to exchange/prospectus, you should carefully consider the following risk factors before deciding whether or not to tender your Santander Mexico shares or Santander Mexico ADSs into the exchange offers. Each of the matters described in these risk factors could have a material adverse effect on the businesses, financial condition and/or results of operations of Santander Spain and Santander Mexico individually or as affiliated companies and on the market price of the Santander Spain ordinary shares.

Risks Relating to the Exchange Offers

The completion of the exchange offers is subject to certain conditions precedent and if these conditions are not satisfied or waived (if waivable) prior to the expiration time, the exchange offers will not be completed.

        The completion of the exchange offers is subject to a number of conditions, including that all governmental approvals and authorizations required in connection with the exchange offers shall have been obtained and shall have not been revoked or amended, modified or supplemented in any way that could reasonably be expected to materially impede or interfere with, delay, postpone or materially and adversely affect the completion of the exchange offers, the absence of any governmental, judicial, legislative or regulatory developments that would adversely impact the ability to consummate the exchange offers, the absence of any material adverse change (or any condition, event or development involving a prospective change) in the business, properties, assets, liabilities, capitalization, shareholders' equity, condition (financial or otherwise), operations, licenses, franchises, permits, permit applications, results of operations, cash flows or prospects of Santander Mexico or any of its subsidiaries, and the satisfaction of other customary conditions as described in this prospectus/offer to exchange under "The Exchange Offers—Conditions to Completion of the Exchange Offers." Santander Spain can provide no assurances that all of the conditions to the exchange offers will be satisfied, or that they will be satisfied in the time frame currently expected. If these conditions are not satisfied or waived (if waivable) prior to the expiration time, the exchange offers will not be completed.

Because the exchange ratio is fixed, the value of the Santander Spain ordinary shares and/or Santander Spain ADSs you will receive as a result of the exchange offers is likely to fluctuate.

        If you tender your Santander Mexico shares or Santander Mexico ADSs in the U.S. exchange offer through the U.S. exchange agent and your Santander Mexico ADSs and/or Santander Mexico shares are acquired in the U.S. exchange offer, you will receive 1.685 Santander Spain ADSs per Santander Mexico ADS and 0.337 of a Santander Spain ordinary share per Santander Mexico share. Each Santander Spain ADS represents one Santander Spain ordinary share. This exchange ratio is fixed and will not be adjusted to reflect any changes in the market prices of any of the securities of either company. As a result, and subject to the potential adjustments described under "The Exchange Offers—Dividend Payments" section, you will receive a fixed number of Santander Spain ordinary shares and Santander Spain ADSs in connection with the U.S. exchange offer, and changes in the market prices of these securities will affect the value of what you will receive.

        The market prices of the Santander Spain ordinary shares, Santander Spain ADSs, Santander Mexico shares and Santander Mexico ADSs are likely to fluctuate before the completion of the exchange offers and this will affect the value represented by the exchange ratio both in terms of the Santander Mexico shares or Santander Mexico ADSs tendered by you or on your behalf and what you will receive in exchange. For example, based on the closing prices on the MSE translated at the U.S.$/Mexican peso exchange rate published on August 2, 2019, the market value of one Santander Mexico share has varied from a low of U.S.$1.35 to a high of U.S.$1.70 between April 11, 2019 (the last

26

Table of Contents

trading day before Santander Spain issued a press release announcing the exchange offers) and August 2, 2019, while, based on the closing prices on the SSE translated at the U.S.$/euro exchange rate published on August 2, 2019, the market value of a Santander Spain ordinary share has varied from a low of U.S.$4.15 to a high of U.S.$5.20 between April 11, 2019 and August 2, 2019.

        The market prices of the Santander Spain ordinary shares, Santander Spain ADSs, Santander Mexico shares and Santander Mexico ADSs are subject to general price fluctuations in the market for publicly traded equity securities and have experienced significant volatility in the past. Market price variations in these securities could result from actual or investors' perceptions of changes in the businesses, financial condition, results of operations or prospects of Santander Spain or Santander Mexico prior to and/or following the exchange offers, regulatory considerations, legal proceedings, exchange rates, general market and economic conditions and other factors beyond the control of Santander Spain or Santander Mexico.

As of the date of this offer to exchange/prospectus, the board of directors of Santander Mexico has not made any recommendation with respect to the exchange offers.

        Santander Mexico is a Mexican company and Mexican law governs the duties and obligations of Santander Mexico's board of directors, a majority of the members of which are, directly or indirectly, appointed by Santander Spain. As of the date of this offer to exchange/prospectus, Santander Mexico's board of directors has not made any recommendation to its shareholders in connection with the exchange offer.

        Under Mexican law, however, within ten business days after the commencement of the Mexican exchange offer, the board of directors of Santander Mexico is required to prepare and disclose (i) an opinion on the price of the Mexican exchange offer, (ii) any conflicts of interests which each of the board members may have, and (iii) if each member will tender his or her Santander Mexico shares as part of the Mexican exchange offer. The opinion of the board of directors of Santander Mexico, described in (i) above, may be accompanied by the opinion of an independent expert. In addition, under U.S. law, within ten business days after the commencement of the U.S. exchange offer, Santander Mexico is required to file with the SEC and distribute to its shareholders a statement indicating whether it recommends in favor of the U.S. exchange offer, recommends against the U.S. exchange offer, takes no position in connection with the U.S. exchange offer or expresses that it is unable to take a position in connection with the U.S. exchange offer. In each case the board is required to explain the reasons for its position.

Santander Spain is the controlling shareholder of Santander Mexico and may have actual or potential conflicts of interest with respect to the exchange offers and additional access to information.

        Santander Spain is the controlling shareholder of Santander Mexico and may have actual and potential conflicts of interest with investors because it currently has the power to elect a majority of the members of the board of directors of Santander Mexico. As a result of its controlling shareholder position, Santander Spain may have access to information that is not in the possession of the general investor.

The rights of the holders of Santander Spain ordinary shares and Santander Spain ADSs are different than the current rights of holders of Santander Mexico shares and Santander Mexico ADSs.

        The rights of holders of Santander Mexico shares are governed by Mexican law, Santander Mexico's by-laws and the rules of the MSE and its ancillary regulations, and the rights of holders of Santander Mexico ADSs are governed by the deposit agreement among Santander Mexico, the Santander Mexico ADS depositary and the holders from time to time of Santander Mexico ADSs issued thereunder (which we refer to as the "Santander Mexico ADS deposit agreement").

27

Table of Contents

        If your Santander Mexico shares and/or Santander Mexico ADSs are acquired in the exchange offers, you will receive Santander Spain ordinary shares or Santander Spain ADSs representing Santander Spain ordinary shares. The rights of a holder of Santander Spain ordinary shares will be governed by Spanish Corporation Law, Spanish corporation regulations, Santander Spain's by-laws and the rules of the SSE, which are different than the rights of a holder of Santander Mexico shares. The rights of a holder of Santander Spain ADSs are governed by the Santander Spain ADS deposit agreement. For a discussion of these differences, see the "Comparison of Rights of Holders of Santander Spain Securities and Santander Mexico Securities" section of this offer to exchange/prospectus beginning on page 110.

        Some of the main differences between the rights of holders of Santander Mexico shares and Santander Spain ordinary shares are: (a) shareholders of Santander Mexico do not have withdrawal rights (derechos de retiro) or any similar rights whereas under Spanish Corporation Law, under certain very limited circumstances, shareholders have such rights; (b) the Mexican Corporation Law and the Spanish Corporation Law differ as to the required quorums for certain corporate matters to be voted at shareholders meetings, as well as to the required voting majorities for them to be approved; (c) under the Securities Market Law (Ley del Mercado de Valores), shareholders owning shares with voting rights, even limited or restricted, for each ten percent stake in Santander Mexico's capital stock held by them, individually or jointly, shall be entitled to: (i) appoint and revoke a member of the board of directors at a general shareholders meeting (such appointment may only be revoked by other shareholders when the appointment of all other directors is revoked, in which case, the individuals substituted may not be so appointed during a period of twelve months immediately following the relevant revocation date), (ii) require the chairman of the board of directors or of the audit committee (comité de auditoria y prácticas societarias) to call a general shareholders' meeting at any time and (iii) request a one-time postponement, for three calendar days and without the need for a new call, of the vote on any matter in respect of which they are not sufficiently informed, while under the Spanish Corporation Law, (y) only shareholders who, individually or acting in concert, own an amount of share capital equal to or above that resulting from dividing the company's share capital by the number of members of the board of directors have the right to appoint directors (in particular, the number of directors resulting from dividing the amount of share capital owned by the minimum required pursuant to the aforementioned formula, rounded down); and (z) in listed companies such as Santander Spain, only shareholders owning, individually and in concert, a 3% or more of the company's share capital have the right to request the call of a shareholders meeting or to supplement the agenda of an already convened meeting; and (d) pursuant to the Mexican Corporation Law, the holders of shares with voting rights, who individually or jointly hold twenty percent or more of the share capital, may judicially oppose the resolutions of the general meetings in respect of which they have the right to vote while according to the Spanish Corporation Law, the percentage entitled to this right in listed companies such as Santander Spain is 0.1%.

The receipt of Santander Spain Securities and cash (if any) pursuant to the exchange offers will be a taxable transaction for U.S. federal income tax purposes.

        The receipt of Santander Spain Securities and cash (if any) in exchange for Santander Mexico Securities pursuant to the exchange offers will be a taxable transaction for U.S. federal income tax purposes. In general, a U.S. investor whose Santander Mexico Securities are exchanged for Santander Spain Securities in the transaction will recognize capital gain or loss for U.S. federal income tax purposes in an amount equal to the difference, if any, between (i) the fair market value of the Santander Spain Securities on the date of the exchange and the cash (if any) received with respect to the Santander Mexico Securities exchanged and (ii) the U.S. investor's adjusted tax basis in the Santander Mexico Securities. A U.S. investor will have a tax basis in the Santander Spain Securities received equal to their fair market value on the date of the exchange, and the U.S. investor's holding period with respect to the Santander Spain Securities will begin on the day after the date of the

28

Table of Contents

exchange. The tax consequences of the transaction and of holding Santander Spain Securities are discussed in more detail below under "Material United States Federal Income Tax Considerations."

You will need to consider the Mexican tax consequences of the transaction and of holding Santander Spain Securities.

        The receipt of Santander Spain Securities in exchange for Santander Mexico Securities pursuant to the exchange offers will be treated as a taxable disposition for Mexican tax purposes. Generally, Mexican resident corporations, Mexican resident individuals and non-Mexican residents whose Santander Mexico Securities are exchanged for Santander Spain Securities in the transaction will recognize gain or loss on the exchange and may be subject to Mexican income tax under any of the particular tax regimes applicable to such types of investors. Gain should generally be computed by comparing the fair market value of the Santander Mexico Securities on the date of the exchange and (ii) the holder's adjusted tax basis in the Santander Mexico Securities computed under each investor's particular regime. A U.S. investor will have tax basis in the Santander Spain Securities received equal to the fair market value of the consideration paid. The tax consequences of the transaction and of holding Santander Spain Securities are discussed in more detail below under "Mexican Tax Consequences."

You will need to consider the Spanish tax consequences of the transaction and of holding Santander Spain Securities.

        If you receive Santander Spain Securities as a result of the exchange offers, you will be subject to certain Spanish tax consequences related to holding such Santander Spain Securities, including the treatment of dividends paid with respect to such Santander Spain Securities and of the proceeds of a sale or disposition of such Santander Spain Securities. In particular, on any dividend payment date, Qualifying Shareholders (as defined below) will be subject to a Spanish withholding tax of 19% on any dividends paid by Santander Spain; however, the Spanish withholding tax rate may be reduced to 10% or to 15% as per the Treaties (as defined below) under certain conditions.

        The Spanish tax consequences of the acquisition, ownership and disposition of Santander Spain Securities by U.S. and Mexican tax residents are discussed in more detail below under "Spanish Tax Consequences." We encourage you to read the discussion under the "The Exchange Offers—Tax Consequences—Spanish Tax Consequences" section of this offer to exchange/prospectus beginning on page 78 for a more detailed discussion of the Spanish tax consequences of your participation in the exchange offers. We also encourage you to consult your own tax advisors concerning the tax consequences of the exchange offers with respect to the Santander Spain ADSs (evidenced by Santander Spain ADRs) (along with their acquisition, holding or disposal) in light of your particular situation.

The proposed financial transactions tax ("FTT") may apply.

        On February 14, 2013, the European Commission published a proposal (the "Commission's Proposal") for a Directive for a common FTT in Belgium, Germany, Estonia, Greece, Spain, France, Italy, Austria, Portugal, Slovenia and Slovakia (the "Participating Member States").

        The scope of the Commission's Proposal is very broad and could, if introduced, apply to some dealings in shares (including secondary market transactions) in certain circumstances. The issuance and underwriting of shares should, however, be exempt.

        However, the Commission's Proposal remains subject to negotiation between the Participating Member States and the scope of any such tax is uncertain. Additional EU Member States may also decide to participate. Spain published a bill of FTT, in which a 0.2% FTT was applicable to specific

29

Table of Contents

secondary market transaction over shares. However, this bill has yet to be passed by the Spanish Parliament.

        Qualifying Shareholders are advised to seek their own professional advice in relation to the FTT.

If the exchange offers are completed, the liquidity and market value of any Santander Mexico shares and Santander Mexico ADSs not acquired by Santander Spain could be adversely affected

        The acquisition of Santander Mexico shares and Santander Mexico ADSs by Santander Spain pursuant to the exchange offers will reduce the number of holders of Santander Mexico shares and Santander Mexico ADSs and the number of Santander Mexico shares and Santander Mexico ADSs that might otherwise trade publicly and, depending on the number of Santander Mexico shares and Santander Mexico ADSs acquired by Santander Spain pursuant to the exchange offers, could adversely affect the liquidity and market value of any remaining Santander Mexico shares and Santander Mexico ADSs held by the public.

        Although Santander Spain does not currently intend to seek delisting of the Santander Mexico ADSs from the NYSE, depending upon the number of Santander Mexico ADSs purchased pursuant to the exchange offers, the Santander Mexico ADSs may no longer meet the standards for continued listing on the NYSE and delisting the Santander Mexico ADSs may be required, which could further adversely affect the liquidity of the Santander Mexico ADSs.

        According to the NYSE's published guidelines, the NYSE would consider delisting the Santander Mexico ADSs if, among other things, (i) the total number of holders of Santander Mexico ADSs falls below 400, (ii) the total number of holders of Santander Mexico ADSs falls below 1,200 and the average monthly trading volume for Santander Mexico ADSs is less than 100,000 for the most recent 12 months or (iii) the number of publicly held Santander Mexico ADSs (exclusive of holdings of officers and directors of Santander Mexico and their immediate families and other concentrated holdings of 10% or more) falls below 600,000. We have been informed by Santander Mexico that as of June 27, 2019, there were 6,208 beneficial holders of 150,801,462 Santander Mexico ADSs, all of which we believe were publicly held under the NYSE definition. Therefore, as of that date, the NYSE would consider delisting the Santander Mexico ADSs if (i) at least 93.57% of holders tendered all of their Santander Mexico ADSs into the U.S. exchange offer, (ii) at least 80.68% of holders tendered all of their Santander Mexico ADSs into the U.S. exchange offer and the average monthly trading volume for Santander Mexico ADSs fell below 100,000 shares for the previous 12 months or (iii) at least 99.61% of publicly held Santander Mexico ADSs were tendered into the U.S. exchange offer. If, as a result of the purchase of the Santander Mexico ADSs pursuant to the U.S. exchange offer, the Santander Mexico ADSs no longer meet the requirements of the NYSE for continued listing and the listing of the Santander Mexico ADSs is discontinued, the market for the Santander Mexico ADSs could be adversely affected.

        We do not have any current intention to cause the deregistration or delisting of Santander Mexico shares. After completion of the exchange offers, any outstanding Santander Mexico shares will continue to trade on the MSE unless Santander Mexico ceases to comply with the Listing Requirements, pursuant to which (a) the CNBV may determine the cancellation of the registration of the shares of Santander Mexico in the RNV, as well as their elimination from the list of securities authorized to be listed on the MSE, and (b) Santander Spain may be required by the CNBV to make an additional offer for Santander Mexico shares, within the following 180 calendar days from the CNBV request. The consideration offered by Santander Spain as part of any such additional offer under applicable Mexican law would be the greater of the average trading price of the Santander Mexico shares for the 30 days prior to such subsequent offer and their book value. We may be able to offer a different price in any such additional offer, subject to prior approval from the CNBV, based upon, amongst other factors, Santander Mexico's financial condition and prospects at the time and after approval of such price by

30

Table of Contents

Santander Mexico's board of directors, taking into consideration the opinion of its Audit and Corporate Practices Committee in accordance with Mexican law. Any such consideration may be different than that offered in the exchange offers. In such scenario, the Mexican Securities Market Law provides that the CNBV may determine the deregistration and delisting of Santander Mexico, if the interests of minority shareholders and the market in general have been adequately protected.

        If the delisting occurs, the amount of publicly available information concerning Santander Mexico and its operations would be reduced and the liquidity of and markets for the Santander Mexico shares and Santander Mexico ADSs would be adversely affected. While the Santander Mexico shares and Santander Mexico ADSs might trade in over-the-counter markets, such markets may not develop and, even if they do, the extent of the public market and the availability of market quotations for these securities are likely to be significantly reduced and would depend upon the number and/or the aggregate market value of, and the interest of securities firms in maintaining a market for, these Santander Mexico Securities.

        Furthermore, even if the Santander Mexico ADSs continue to be listed on the NYSE and the Santander Mexico shares continue to be listed on the MSE, the number of Santander Mexico shares and Santander Mexico ADSs that are publicly held by shareholders other than Santander Spain or its affiliates may be so small that the liquidity of such securities may be significantly reduced, there may no longer be an active trading market for the Santander Mexico shares and Santander Mexico ADSs and their market value may be significantly reduced.

        As a result of the foregoing, you should not assume that the Santander Mexico ADSs will continue to be listed on the NYSE or that the Santander Mexico shares will continue to be listed on the MSE, or that there will be a liquid and active trading market or a continuation of current price levels for such securities after completion of the exchange offers.

31

Table of Contents

SELECTED FINANCIAL DATA OF SANTANDER SPAIN

        The following table presents selected historical consolidated financial data of Santander Spain as of and for each of the years ended on December 31, 2018, 2017, 2016, 2015 and 2014 and as of, and for the six-month periods ended June 30, 2019 and 2018. We have selected the following financial information from our consolidated financial statements. You should read this information in connection with, and it is qualified in its entirety by reference to, our audited consolidated financial statements included in Part II of the Santander Spain 2018 Form 20-F and the unaudited interim condensed consolidated financial statements included in the Santander Spain Second Quarter Results Form 6-K. The selected historical consolidated financial information as of and for the years ended on December 31, 2018, 2017, 2016, 2015 and 2014 and as of, and for the six-month periods ended June 30, 2019 and 2018 was prepared in accordance with IFRS as issued by the IASB and has been derived from the Santander Spain 2018 Form 20-F and Santander Spain Second Quarter Results Form 6-K, respectively, which are incorporated by reference into this offer to exchange/prospectus. The audited annual consolidated financial statements of Santander Spain as of and for the years ended December 31, 2018, 2017 and 2016 have been audited by Santander Spain's independent registered public accounting firm, PricewaterhouseCoopers Auditores, S.L., as indicated in its reports on those consolidated financial statements, which are included in the Santander Spain 2018 Form 20-F and in other reports previously filed by Santander Spain with the SEC. For more information about how to obtain copies of the Santander Spain 2018 Form 20-F or the Santander Spain Second Quarter Results Form 6-K, see the "Where You Can Find More Information" section of this offer to exchange/prospectus beginning on page 11.

        You should read the information below in conjunction with Santander Spain's audited annual consolidated financial statements and unaudited interim condensed consolidated financial statements and the notes thereto, as well as the "Presentation of Financial and Other Information" and "Operating and Financial Review and Prospects" sections in the Santander Spain 2018 Form 20-F and

32

Table of Contents

the "Introduction, Basis of Presentation of the Interim Condensed Consolidated Financial Statements and Other Information" section in the Santander Spain Second Quarter Results Form 6-K.

33

Table of Contents