Annex 24 and Annex 30: inventory control for IMMEX companies

For a company with an IMMEX program (Mexico's Manufacturing, Maquiladora and Export Services program), inventory control is not an administrative matter: it is how you prove to the authority what happened to every temporarily imported good. When that control fails, shortages can turn into unpaid duties, fines and, in serious cases, suspension of the program.

Annex 24: the foundation for every IMMEX company

Annex 24 sets out the guidelines for the automated inventory control system that IMMEX companies, among others, must maintain. In practice, the system must allow you to trace:

• Inbound temporarily imported goods, linked to their customs entry (pedimento).
• Transformation, based on bills of materials that show which inputs each product consumes.
• Outbound movements, whether returned abroad, changed to another regime or transferred.
• Discharges, that is, cancelling import balances against exports.
• Scrap and waste, with the corresponding treatment and evidence.

The information must be available to the authority and consistent with customs entries and accounting records.

Annex 30: an additional level of detail

Annex 30 relates to the electronic system used to control the credit and guarantee accounts of companies holding the VAT and IEPS Certification, depending on their tier. It requires greater detail and reconciliation, because the tax credit the company applies to its temporary imports depends on that control.

Not every IMMEX company is subject to Annex 30. It depends on the certification modality, so it should be reviewed case by case.

Why balances do not reconcile

In practice, the most frequent problems are not in the software but in the data that feeds it:

1. Outdated bills of materials. If the product changed and the bill did not, discharges will be wrong.
2. Inconsistent units of measure across purchasing, production and customs entries.
3. Unrecorded scrap and waste, or no evidence of their final destination.
4. Amended customs entries that are not reflected in the system.
5. Manual uploads without review controls.

The result is a theoretical inventory that matches neither the physical count nor the customs records.

How to build reliable control

• Diagnose before switching systems. A new system fed with the same data will produce the same errors.
• Clean up historical balances with a documented reconciliation of customs entries, inventory and accounting.
• Assign owners for each data source: foreign trade, production, warehouse and accounting.
• Document procedures for uploads, discharges and scrap handling.
• Schedule periodic reviews, not just before an audit.

Delour's role

Delour does not sell inventory software. We are vendor-independent: we assess your current system, define the requirements it must meet, coordinate with your technology vendor and verify that the information is complete and consistent.

If your company holds IMMEX and you want to know how solid your control is, request an assessment or learn about our Annex 24 and Annex 30 service.