Anexo 24 Explained in Plain English: Inventory Control for IMMEX Operations
People tend to file Anexo 24 mentally next to “more customs paperwork.” That framing is why it goes wrong. Anexo 24 is not a folder. It is the inventory-control system that proves your IMMEX story holds together — that what you imported temporarily actually became product you exported.
If you work in operations, the warehouse, ERP, or compliance, this is the record that has to agree with everything you do day to day.
What Anexo 24 is for, in one breath
An IMMEX program lets you defer import taxes on materials that will leave again as exports. Anexo 24 is the automated inventory-control system that has to demonstrate that connection: what came in, what it was used for, what was consumed or scrapped, what was exported, and what is still on hand.
It is less an archive than a running balance. Every import adds to it. Every export, transfer, or change of regime draws it down. The balance is supposed to reflect reality.
Why it drifts
The drift almost never comes from Anexo 24 itself. It comes from the systems feeding it. Your ERP, your warehouse management, and your customs broker all describe the same physical goods, and they do not always describe them the same way.
Composite scenario: This example combines recurring data-reconciliation patterns seen in cross-border manufacturing workflows. It is not a statement about any specific company.
Take one part across four systems on the same week:
| System | What it shows | Why it differs |
|---|---|---|
| ERP | 10,000 received | Booked from the PO at order quantity |
| Warehouse count | 9,850 on hand | 150 still in inspection, not yet put away |
| Customs / broker file | 10,000 imported | Matches the import, in pieces |
| Anexo 24 | 9,600 | Loaded from an older master-data mapping |
Every number has a reason. None of them is fraud. But if no one reconciles the reasons, the Anexo 24 balance slowly stops matching the plant, and a year later that gap is the thing you have to explain.
The habit that keeps it honest
The single most useful practice is a periodic reconciliation between Anexo 24, the ERP, and a physical count, with a named owner and a written explanation for every difference. Not a perfect match — differences are normal — but an explained match. Inspection holds, in-transit material, scrap timing: all legitimate, all reconcilable, if someone writes them down.
What to check first
- Does one part have one part number and one unit of measure across ERP, warehouse, and Anexo 24?
- Who loads data into Anexo 24, and from which source?
- When was the last reconciliation between Anexo 24, ERP, and a physical count?
- Are scrap and inspection differences recorded against the right import?
Questions for your specialist
- How often should we reconcile Anexo 24 against ERP and physical inventory for our volume?
- How should we document explained differences so they hold up later?
- What unit-of-measure and BOM conventions keep Anexo 24 aligned with production?
Direct these to a customs broker or IMMEX specialist who can see your actual setup.
Before you escalate
If your Anexo 24 balance and your physical inventory disagree by an amount you cannot explain in a sitting, do not keep stacking months on top of it. Pull one part, build the four-system view above, and take that to a specialist. A concrete, single-part reconciliation is far easier to act on than a vague “our numbers are off.”
Quick bilingual glossary
If you work with a Mexican plant or broker, these Spanish terms come up constantly:
| Spanish term | What it means for a foreign buyer |
|---|---|
| Anexo 24 | The inventory-control annex of Mexico’s foreign-trade rules (RGCE) |
| Control de inventarios | The inventory-control system tied to temporary imports |
| Pedimento | The Mexican customs declaration for an import or export |
| Descargo | ”Discharge”: recording that imported material was exported or consumed |
| Merma / desperdicio | Scrap / waste that still has to be accounted for |
| SCCCyG (Anexo 31) | The credit-and-guarantee control tied to VAT/IEPS certification |
Interactive tools and visuals
Reconciliation aids
Use these pages to compare inventory movement, tax credit/guarantee control and source documents before drawing conclusions.
The output flags points to verify; it does not determine compliance.
Related reading
- Anexo 24 vs Anexo 31: Why Your Inventory and Tax Credit Records May Not Match
- ERP, Warehouse, Broker, and Anexo 24 Mismatch: A Practical IMMEX Scenario
- Pedimento Reconciliation for IMMEX: What to Check Before the Numbers Drift
- Scrap, Mermas, and Waste Under IMMEX: Why Production Losses Need a Data Trail
- IMMEX risk and data reconciliation index
Sources & further reading
- SAT — Reglas Generales de Comercio Exterior — RGCE and annex reference for inventory-control obligations.
- Diario Oficial de la Federación — Publication source for the RGCE and Anexo 24 text.
- SNICE / Secretaría de Economía — IMMEX — IMMEX program and temporary-import context.
- SAT — Foreign trade references — Customs and certification reference material.
Disclaimer
This article is for educational purposes only. It is not legal, tax, customs, or accounting advice. IMMEX, import, VAT/IEPS, Anexo 24, Anexo 31, NOM, Padrón, RFC, and customs-broker obligations depend on the facts of each operation. Confirm requirements with your Mexican importer, customs broker, tax advisor, or qualified IMMEX specialist before shipping or changing your process.