Client Alert- Mexican Court Shifts Burden of Proof to Service Providers in E-Commerce Disputes.

Key Takeaway

In a landmark isolated thesis I.5o.C.202 C (11a.) published by the Mexican Supreme Court on October 24, 2025, the Mexican judiciary established that the burden of proof lies with the service provider in disputes concerning the nullity of electronic transactions charged to a client’s account administered by that provider.

This precedent marks an important shift in how courts will evaluate consent and authentication in online transactions and digital contracting within Mexico’s growing e-commerce landscape. 

Background 

The case arose from a commercial dispute where a client challenged various charges made through an online account managed by a courier and logistics provider. The plaintiff claimed not to have authorized those transactions.

The first-instance court declared the charges null, finding that the service provider failed to prove that the client had indeed executed the operations using their registered username and password.

On appeal, the Fifth Collegiate Civil Court confirmed that it is the provider—not the customer—who must demonstrate that the disputed operations were validly authorized through the proper use of the authentication mechanisms agreed with the user.

Legal Reasoning 

The Court relied on Articles 90 and 90 Bis of the Mexican Commercial Code, which regulate electronic data messages and their legal presumption of authorship.

It reasoned that:

• The dynamic burden of proof principle applies when one party (in this case, the consumer or user) faces difficulty obtaining evidence in its possession or control.
• Because the provider manages the electronic platform and holds access to system logs, digital evidence, and authentication data, it is in the best position to demonstrate whether consent was validly expressed.
• Therefore, the provider must produce all relevant technical and documentary evidence, including expert analysis in digital forensics, to show that the disputed transactions were properly executed.

Implications for Businesses

This decision represents a significant precedent for companies engaged in e-commerce, fintech, and online service delivery in Mexico.

Providers should:

• Reassess authentication protocols (e.g., passwords, OTPs, digital signatures) and ensure traceability and data integrity.
• Maintain detailed transaction logs and metadata evidencing user consent.
• Implement robust data retention policies aligned with commercial, privacy, and cybersecurity regulations.
• Prepare for increased litigation risk where users challenge the validity of digital contracts or charges.

Failure to maintain proper evidentiary support may result in courts declaring electronic transactions null and void, even when the provider believes they were properly authorized.

Conclusion

This ruling underscores the growing judicial expectation that e-commerce and digital service providers proactively safeguard consumer rights and transparency in online contracting. As Mexico continues to modernize its digital commerce framework, companies should anticipate closer judicial scrutiny of electronic consent and authentication processes.

At FisherBroyles, we are closely tracking this development and its potential implications for our clients.

We stand ready to assist e-commerce platforms, general counsel, and innovators in navigating the shifting Mexican and Latin American legal landscape.

For additional information, please contact any of the following:

Sergio Legorreta at [email protected] with any questions or more specific situations.

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