New Digital Authentication Process for the Mexican Institute of Social Security

Quick Hits

• The Mexican Tax Authority’s tax electronic signature (e.firma) will now be the only digital credential for ALL employer procedures before the Mexican Institute of Social Security (IMSS).
• Employers have until October 14, 2026, to update their credentials.

The agreement (ACDO.AS2.HCT.160726/3.P.DIR) is the result of a transition process intended to digitalize all IMSS processes.

Main Modifications and Procedures

The implementation of this agreement represents that the e.firma will be the only valid certificate for authenticating an employer’s identity for any IMSS procedure and that legal representation of a company must be managed through the IMSS Virtual Desktop using the legal representative’s company’s e.firma to access.

As a consequence of the latest requirements, the IMSS digital certificates will no longer exist as the Employer Electronic Identification Number (Número Patronal de Identificación Electrónica) (NIPE)).

The following are some of the procedures that will be affected by this disposition:

• Affiliation movements (enrollments, cancellations, and salary modifications)
• Risk premium determination
• Payment receipts of social security contributions (SUAs)
• Access to the IMSS’s mailbox

Tips for Ensuring Future Compliance

The same agreement grants employers a ninety-day period, which will elapse on October 14, 2026, to incorporate e.firma to be in compliance and to avoid any fines related to the compliance of other obligations.

Before the ninety-day period elapses, employers may want to ensure that they have taken the following actions:

1. Verify that the e.firma of the company and of the legal representative is active.
2. Link the e.firma to the Employer Registration Number at the IMSS Virtual Desktop.
3. Designate and link the legal representative’s e.firma.

The employer’s representative must have an e.firma that has been duly updated; otherwise, the link cannot be properly executed.

Ogletree Deakins’ Mexico City office will continue to monitor developments and will provide updates on the Cross-Border blog as additional information becomes available.

Pietro Straulino-Rodríguez is the managing partner of the Mexico City office of Ogletree Deakins.

Natalia Merino Moreno is an associate in the Mexico City office of Ogletree Deakins.

María José Bladinieres is a law clerk in the Mexico City office of Ogletree Deakins.

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