A commercial contract does not lose validity merely because it is entered into online, but the word “I accept” does not by itself resolve every problem of proof either. In Mexico, the Commercial Code recognizes data messages and electronic signatures under principles of attribution, integrity and reliability. For a company, the practical challenge is to prove who accepted, which version they accepted and whether the document remained intact. Civil, labor, consumer or specially-formal contracts must be reviewed under their applicable legislation.
Electronic validity does not mean automatic proof
The Commercial Code provides that legal effects cannot be denied to information solely because it is contained in a data message. When the law requires a signature, the requirement may be satisfied with a method that identifies the signer, indicates their approval and is as reliable as is appropriate for the purpose and circumstances. This allows the use of everything from simple mechanisms to advanced signatures, depending on the risk. However, some acts retain special formalities, such as notarial intervention, registration or documents with sector-specific requirements. Before digitizing a process, the contract must be classified and it must be confirmed whether the electronic form covers all its elements, annexes, authorizations and external formalities.
The evidence must reconstruct the consent
A robust digital file keeps the exact version of the contract, the declared and verified identity, the authentication method, the date and time, the delivery address, reading and signing events, certificates, digital hashes and a record that the annexes were available. It also documents the process to correct errors and delivers a copy to the signer. In the conflicting-precedents case 128/2018, concerning bank-card transactions authorized by PIN, the Supreme Court analyzed the simple electronic signature, the reliability of the method and the attribution of the transaction; it is a useful precedent, but not an automatic rule for any platform or contract. That is why a pasted image of a signature offers fewer guarantees than a flow with access controls, two-factor authentication, an audit log and tamper-proof evidence.
Preservation is part of contracting
NOM-151-SCFI-2016 sets out methods to preserve data messages and digitize documents linked to commercial acts. Depending on the case, a certificate issued by a certification-services provider may reinforce the demonstration of existence and integrity over time. The company must define retention periods, backups, permissions, recovery and incident response, in addition to complying with privacy and security. The contract with the signing platform also matters: it must clarify the availability of evidence, export, continuity and data processing. The correct strategy is not to use the most complex technology, but to choose a level of certainty proportional to the value, duration and possibility of dispute.
Key points
- Data messages may have legal effects and be used as evidence in commercial matters.
- The reliability of the identification method must be proportional to the risk and purpose of the contract.
- An isolated visual signature is less solid than a complete log of authentication and integrity.
- Preservation under technical rules is part of the contract design, not a later task.
What to review
- Classify contracts by amount, duration, formalities and risk of impersonation or dispute.
- Set up an exportable file with the version, annexes, authentication, time stamps and log.
- Review contracts with signing providers to ensure access, preservation, security and portability.