Pursuant to Article 59, Section I, of the Mexican Customs Law (Ley Aduanera), companies operating under an IMMEX program are required to implement and maintain an automated inventory control system that preserves, at all times, an up-to-date record of all foreign trade goods data, which must remain available to the customs authority upon request.

This obligation is not new, but its practical scope has intensified considerably. Compliance with Annex 24 evidences that goods introduced under the temporary importation regime — authorized to remain in Mexican territory for a period generally not exceeding 18 months — were effectively returned abroad within the permitted timeframe.

When a company cannot demonstrate this, the authority applies a legal presumption with very serious consequences: it considers those goods to be irregularly present in Mexico without the taxes applicable to a definitive importation having been paid.

If the company fails to demonstrate an automated, up-to-date inventory control system, the customs authority may presume that all goods in the taxpayer’s possession or custody, as well as those sold since the date of importation, are of foreign origin — including those analogous or identical to the imported goods.

When the discharges corresponding to temporarily imported goods have simply not been registered in the system.

En cualquiera de estos dos casos, la autoridad procede a determinar contribuciones omitidas e imponer las sanciones correspondientes.

The consequences of failing to update Annex 24 are numerous and escalating in nature. They begin with formal information requests and can lead to proceedings that jeopardize the entire operation of the company.

Consequences 16, 17, and 18 represent the most severe outcome: they may entail criminal liability for company officers and the complete suspension of all foreign trade operations. Reinstating the VAT and IEPS Certification or the IMMEX program once cancelled requires time, significant resources, and a complex legal defense process.

Effective November 2024, Section C of Annex 24 introduces a particularly significant obligation for companies holding a VAT and IEPS Certification: granting the Tax Administration Service (Servicio de Administración Tributaria, SAT) direct and remote access to their inventory control systems.

This provision operates on two levels that fundamentally transform the nature of compliance:

The SAT can audit and verify compliance with all corresponding obligations on a continuous basis and without prior notice.

The immediate consequence of the SAT detecting inconsistencies through this real-time access is the initiation of proceedings for the Cancellation of the VAT and IEPS Certification. From the moment such proceedings are formally notified and until a final resolution is issued, all benefits derived from the certification are suspended — an outcome with significant operational and financial consequences for the company.

Real-time SAT access eliminates the margin for late corrections. The only effective strategy is prevention: identifying and remedying findings before the authority detects them. Once a cancellation proceeding is initiated, the costs of legal defense and the operational impact are significantly greater.

Given the critical importance of these obligations and the severity of the consequences arising from non-compliance, monitoring Annex 24 cannot be sporadic or reactive. Companies that wait for a formal request before reviewing their compliance status are operating under an unnecessary and unjustified level of risk.

Experience in audit proceedings and legal defense consistently demonstrates that findings identified internally are always easier — and considerably less costly — to correct than those detected by the authority.

Companies must implement periodic preventive review actions aimed at identifying findings or deviations in a timely manner, with the objective of remedying them before the authority detects them — thereby preventing the imposition of penalties and the materialization of the consequences described throughout this analysis.

A comprehensive program of preventive auditing, continuous monitoring, and specialized advisory services designed to stay ahead of SAT and ANAM enforcement priorities.

• Annex 24 audit and monitoring: BOMs, discharge records, and balances
• Annex 19 and 22 review: customs entries, tariff classifications, and declared contributions
• IMMEX program obligations: RAOCE, INEGI reports, export percentages, and return notices
• VAT and IEPS Certification: ongoing obligations and renewal management
• Annex 30 / SCCCyG: reconciliation with SAT account statement
• Foreign-origin fixed assets: physical inventory and documentary integration
• Electronic file and operational substance documentation
• Specialized legal consulting, staff training, and regulatory updates

CUSTOMS LEGAL DEFENSE

Representation in Tax Audit and Enforcement Proceedings

Specialized representation and effective defense against any customs authority action, backed by our extensive experience on both sides of the enforcement process.