For companies operating under Mexico’s IMMEX program, managing the deferral of import duties is a primary benefit. However, a crucial aspect of fiscal compliance involves the Value-Added Tax (VAT, or IVA) and the Special Tax on Production and Services (IEPS). This requires adherence to the Annex 31 IMMEX framework for fiscal control.
Annex 31 refers to a specific regulatory mechanism and its associated automated system, which is administered by Mexico’s Tax Administration Service (SAT). Its function is to control the fiscal credits for VAT and IEPS that are granted to certified IMMEX companies. Understanding this system is fundamental for maintaining compliance.
This guide provides a technical overview of the Annex 31 IMMEX system, its mechanics, and its direct relationship with a company’s inventory management responsibilities.
What is Annex 31?
The Annex 31 IMMEX system is formally known as the “System for Control of Accounts for Credits and Guarantees” (SCCCyG). This is an online platform managed by the SAT that monitors the VAT and IEPS liabilities for IMMEX companies that have successfully obtained a “VAT Certification.”
Companies with this certification receive a 100% fiscal credit on the VAT and IEPS that would otherwise be due on their temporary imports. Annex 31 is the government’s tool to track this tax credit. It provides the SAT with a transparent, ongoing record of a company’s potential tax liabilities tied to its inventory of temporarily imported goods.
Essentially, Annex 31 acts as a live ledger for each company, tracking the potential tax liability from the moment goods enter Mexico until they are confirmed as exported.
The Mechanics of the Credit and Debit System
The core of the Annex 31 IMMEX framework is its automated system of credits and debits. The process works as follows:
- Credits (Cargos): When a certified company processes a temporary importation, the SAT’s Annex 31 system automatically logs a “credit” in that company’s account. The value of this credit equals the amount of VAT and/or IEPS that was deferred on the import. This credit represents a fiscal liability held by the company.
- Debits (Descargos): When the company proves that the imported materials have been exported (as part of a finished product, returned, or transferred to another IMMEX entity), it submits discharge information to the SAT. This action creates a “debit” in the Annex 31 system, which serves to cancel the corresponding initial credit.
The main operational goal for an IMMEX company is to consistently manage its reporting to ensure all credits are correctly discharged with corresponding debits within the legally mandated timeframes. Any unresolved credit signifies that goods are unaccounted for, making the associated tax amount due.
The Link Between Annex 24 and Annex 31 IMMEX Compliance
Proper management of the Annex 31 IMMEX requirements is directly dependent on a well-maintained Annex 24 system. The synchronization between these two annexes is a cornerstone of compliance.
- Annex 24 is the company’s mandatory, internal inventory control system. It is responsible for tracking the physical and logical status of all temporary imports.
- Annex 31 is the SAT’s external fiscal control system, which tracks the tax credits associated with that inventory.
The discharge reports and data generated from a company’s Annex 24 system are the basis for the information submitted to the SAT to clear the credits in the Annex 31 system. Any inconsistency between the internal inventory data (Annex 24) and the external fiscal account (Annex 31) is a major compliance red flag.
Compliance and Reporting Obligations
To comply with the Annex 31 IMMEX framework, companies must follow a strict reporting cadence. They are obligated to submit a report of their discharges to the SAT portal on a monthly basis, detailing all temporary imports that were resolved during that period.
The accuracy of this data is critical. Errors related to part numbers, customs values, quantities, or reporting dates can cause mismatches that leave unresolved credits on the company’s account. If these credits are not discharged before the legal deadline for the temporary import expires (e.g., 18 months), the fiscal benefit is lost, and the tax becomes payable.
In summary, the Annex 31 IMMEX system is the central mechanism for the fiscal supervision of certified companies. Its function as an automated credit and debit ledger requires that businesses maintain perfect alignment between their internal inventory systems and their external reporting to the tax authority.
