eSignature Legality Guide

An “electronic signature” refers to any electronic data that is included in, attached to, or logically associated with a data message by any technological means, and is used to identify the signer and indicate their approval of the information in the data message. Such signatures have the same legal effect as handwritten signatures and are admissible as evidence in court.

A “data message” is defined as information that is generated, sent, received, or stored by electronic, optical, or any other technological means.

Under Mexican law, an electronic (digital) signature is considered “advanced” if it meets the following criteria:

• The signature creation data, in the context in which it is used, is unique to the signer;
• The signature creation data was, at the time of signing, under the exclusive control of the signer;
• It is possible to detect any alteration to the electronic signature (tamper-evident) after the signature was made;
• With respect to the integrity of the data message, any modification to the electronic signature after signing can be identified; and
• It includes a digital certificate issued by a government-authorized certification provider.

If the law requires a document to be in writing, the data message containing the information must satisfy the following conditions to be enforceable:

• It must be preserved in its original form;
• It must be maintained and available for future reference; and
• The electronic signature must be attributable to the signers;

According to the Mexican Civil Code and Commerce Code, an electronic signature is valid for expressing consent or agreement in any legal act between private parties. As long as the electronic signature meets the legal definition and requirements, there are no restrictions on its form or appearance.

In Mexico, electronic signatures are commonly used for transactions between private parties that are not subject to oversight, regulation, or submission to a government authority. For documents that may eventually need to be filed with a government agency, it is generally not recommended to use electronic signatures. With the exception of government filings, most documents can be signed electronically.

Mexican law does not grant advanced electronic (digital) signatures greater legal weight. In the event of a dispute, the party seeking to enforce an electronic signature—including an advanced electronic (digital) signature—must prove its validity, unless the advanced signature includes a digital time-stamp attached to the document.