July 16th 2026
On July 16, 2026, the Official Journal of the Federation (DOF) published the “Acuerdo ACDO.AS2.HCT.290626/176.P.DIR, issued by the Governing Board (H. Consejo Técnico) of the Mexican Social Security Institute at its regular session held on June 29, 2026, regarding the implementation of the e.firma as the sole digital certificate valid for carrying out membership/affiliation transactions (movimientos afiliatorios) and for linking legal representatives exclusively through the Virtual Desk (Escritorio Virtual).”
The Agreement approves the exclusive use of the Advanced Electronic Signature (e.firma), whose digital certificate is issued by the Tax Administration Service (SAT), for the acts that employers or other obligated parties carry out before IMSS through electronic means, granting such acts the same legal effects and evidentiary value as documents signed by hand (autograph signature).
Likewise, the Agreement provides that the linking of legal representatives, officers, or any person authorized to act on behalf of and for the account of the employer must be carried out exclusively through the Virtual Desk, for which both the representative and the represented party must authenticate and sign jointly using their respective e.firma.
Consistent with the foregoing, the Agreement repeals the use of the Employer’s Electronic Identification Number (Número Patronal de Identificación Electrónica, or NPIE) and its digital certificate issued by the Institute, rendering Agreements No. 43/2004 and 533/2006 without effect.
A 90-calendar-day transition period is granted, beginning on the date the Agreement is published in the DOF, for employers and other obligated parties to migrate to the exclusive use of the e.firma. The Agreement will enter into force on the day following its publication—that is, on July 17, 2026.
In summary, once the Agreement enters into force:
- The e.firma (issued by SAT) will be the sole digital certificate valid for authenticating and electronically signing affiliation transactions and other acts carried out before IMSS through electronic means.
- The linking of legal representatives and officers may only be carried out through the Virtual Desk, using the e.firma of both the represented party and the representative.
- The NPIE and its digital certificate will be rendered without effect; companies still using them must migrate to the use of the e.firma within the 90-calendar-day transition period.
- Employers are advised to verify the validity of their e.firma and, as applicable, that of their legal representatives, and to formalize the linking process through the Virtual Desk within the transition period.
The attorneys of the Social Security practice area remain at your disposal to advise you on the implementation of and compliance with the provisions of the Agreement.
Sincerely,
Gil Zenteno
zenteno@basham.com.mx
Gabriela Méndez
gmendez@basham.com.mx
Jesús Carmona
jacarmona@basham.com.mx