Banco Santander Mexico S A Institución de Banca Múltiple Grupo Financiero Santander Mexico : BSMX – Shareholders' letter

Mexico City as of May 10 2021

Dear Shareholder:

I inform you that the Board of Directors of Banco Santander México, S.A. Institución de Banca Múltiple, Grupo Financiero Santander México (Santander México) has called for a General Ordinary and Extraordinary Shareholders' Meeting "the Meeting" to be held on June 9, at 12:00 hours, in which it will be submitted for approval of the shareholders:

1. Approval for the payment of a cash dividend to shareholders of the Santander Mexico.
2. The cancellation of the registration in the National Securities Registry (Registro Nacional de Valores) as well as the listing on the Bolsa Mexicana de Valores, S.A.B. de C.V., of all the shares representing Santander Mexico's capital stock.
3. Designation of special delegates to formalize and execute the resolutions adopted by Shareholders' Meeting.

The call to celebrate the Meeting was published last May 10 by publication made in the electronic publications system for corporations of the Ministry of Economy (Secretaría de Economía).

The enclosed proxy card contains instructions on how to vote your shares for the General Ordinary and Extraordinary Shareholders' Meeting to be held June 9, 2021.

Voting is very important, both to the company and to you as a shareholder. We urge you to vote as soon as possible.

All the information regarding the Meeting is available at: www.santander.com.mx/ir/asambleas/. For any clarification, you can contact Investor Relations of Santander México through the mailbox investor@santander.com.mx

Finally, Santander Mexico hired Morrow Sodali, to answer any question or concern that you may have in relation to the agenda to be discussed at the Meeting. You can reach them at santander@morrowsodali.comor by calling the following:

• Shareholders Call Toll Free: (800) 662-5200
• Banks & Brokers Call Collect: (203) 658-9400

Thank you very much for your trust.

Yours truly,

_______________________

Lic. Fernando Borja Mujica

Secretary of the Board of Directors