Mexico: The e.firm digital signature will be the only valid digital authentication for online social security procedures

As part of the simplification and standardization of electronic identification mechanisms, the Mexican Social Security Institute published an agreement in the Official Gazette of the Federation on July 16, 2026, establishing the exclusive use of the Advanced Electronic Signature (e.firm digital signature), issued by the Tax Administration Service (SAT), for employers and legal entities required to comply with the Mexican Social Security Institute (IMSS) to conduct digital procedures through the official portal for online social security transactions and inquiries.

As a result, the use of the Employer Electronic Identification Number (NPIE) and digital certificates issued by the Institute itself for conducting electronic procedures has been eliminated.

The agreement also stipulates that when a company authorizes a legal representative, administrator, or agent to carry out procedures on its behalf, the linking process must be carried out exclusively through the IMSS Virtual Desktop. In this process, both the legal representative and the represented company must authenticate themselves and sign electronically using their respective e.firms digital signatures.

To transition to this scheme, the Institute granted a period of 90 calendar days from the date of publication of the agreement for companies and any other obligated parties to migrate to the exclusive use of the e.firm digital signature.

In light of these changes, it is important for companies to review their processes and mechanisms for accessing IMSS digital services in a timely manner to ensure an orderly and smooth transition.