IMSS field auditors may assess the real contribution wage base
Field audits. Auditors are empowered to assess documents and information during the audit to determine whether the workers' contribution wage base differs from the one on which the employer pays the corresponding employer-employee contributions.
Official heading (Spanish): VISITAS DOMICILIARIAS. LOS VISITADORES TIENEN LA FACULTAD DE VALORAR DOCUMENTACIÓN E INFORMACIÓN EN SU DESARROLLO PARA DETERMINAR SI EL SALARIO BASE DE COTIZACIÓN DE LAS PERSONAS TRABAJADORAS ES DIFERENTE A AQUEL CONFORME AL CUAL EL PATRÓN CUBRE LAS APORTACIONES OBRERO-PATRONALES CORRESPONDIENTES.
The ruling
IMSS issued a tax assessment after field auditors concluded that the real contribution wage base differed from the one reported and set it on a presumptive basis. The employer argued the auditors exceeded article 46, section IV, of the Federal Tax Code. The Collegiate Circuit Court held that the provision empowers auditors to assess the taxpayer's and third parties' documents, including their suitability and scope.
Our take
The argument that field auditors merely record facts and cannot weigh evidence no longer holds after the 2020 amendment to article 46 of the Federal Tax Code. For employers, the decisive window is the period after the last partial audit report: evidence not filed then, or filed without adequate support, is hard to rescue later. In our experience, wage base gaps come from bonuses, vouchers and items not properly integrated. Review integration before an audit, not during one. The ruling still leaves room to argue whether the issuing authority gave its own reasons for what it adopted.
What to do
- Review how the contribution wage base is integrated, especially bonuses, vouchers and variable benefits.
- Prepare the response to the last partial audit report with complete, organized documentary evidence.
- When challenging, check whether the assessment independently explains the presumptive determination.
Details
- Court
- Collegiate Circuit Court
- Type
- Isolated precedent
- Identifier
- XVI.2o.A.6 A (12a.)
- Digital registry
- 2032477
- Published
- August 7, 2026
- Area
- Tax
- View official source ↗
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Prepared by Artegia for information only; not legal advice. Headings in English are unofficial translations. The official text is the one published in the Semanario Judicial de la Federación or the TFJA journal.