IMMEX Retention Deadlines in Mexico: 18 Months, 6-Month Virtual (V1) Trap & Fixed Assets

Every temporary import into a Mexican IMMEX plant carries a ticking statutory clock. Because the General Import Duty (IGI) is deferred under Article 108 of the Mexican Customs Law (Ley Aduanera) and the 16% VAT is credited under Article 28-A of the VAT Law, the Mexican government requires each lot of imported material to be transformed and returned abroad (or formally converted to definitive import status) before its statutory retention period (plazo de permanencia) expires.

In Anexo 24 and Anexo 30/31 (SCCCyG), that clock starts on the exact entry/modulation date of the import pedimento and discharges on a strict First-In, First-Out (FIFO / PEPS) basis. If a single lot of raw material sits in your Mexican warehouse or ERP one day past its legal deadline, it automatically triggers Expired VAT Credits (Créditos Vencidos) in SCCCyG and exposes the plant to customs fines and seizure.

1. Master Reference Table: All IMMEX Permanence Deadlines by Merchandise Category

Contrary to the popular belief that “all IMMEX raw materials have 18 months,” Article 108 of the Customs Law, Article 4 of the IMMEX Decree, and Title 4 / Title 7 of the RGCE establish five distinct retention windows depending on what you import, how it entered (IN vs. V1), and whether your plant holds OEA certification:

2. The #1 Compliance Trap in Mexico: The 6-Month Rule on Virtual Pedimentos (V1)

Look closely at Row 2 of the table above. Over 60% of expired-inventory crises in Mexican plants stem from Article 4 (final paragraph) of the IMMEX Decree and RGCE Rule 4.3.21, Section II, compounded by SAT’s July 24, 2020 reform to the RGCE.

Here is how the trap snaps shut on a US-owned plant:

1. Your Mexican plant holds an active IMMEX program and an IVA/IEPS Certification (Rubro A, AA, or AAA), but does not hold OEA (Authorized Economic Operator) certification.
2. Instead of importing plastic housings or stamped metal brackets directly across the Laredo bridge on an IN pedimento (which gets 18 months), your purchasing manager buys them from a Tier-2 injection molder located in Monterrey or Querétaro that also has IMMEX.
3. To bill at 0% VAT and transfer the customs liability, the Monterrey supplier and your plant execute a Virtual Transfer (V1 pedimento).
4. Your ERP and warehouse team assume those parts have 18 months (or assume their Rubro AA/AAA status still gives them 36 months, as it did prior to July 2020). In reality, because the July 24, 2020 RGCE reform repealed the 36-month extension from Rule 7.3.1 (IVA/IEPS) and restricted it to OEA companies under Rule 7.3.3, Section XXV, any V1 virtual import between IMMEX plants for a non-OEA company expires in exactly 6 months!
5. Even worse: inside SAT’s SCCCyG (Anexo 30/31), on Day 181, SCCCyG automatically moves the 16% VAT credit on that V1 pedimento into the Créditos Vencidos (Expired Credits) column, triggering an AGACE requirement notice that threatens to suspend your IVA/IEPS Certification.

How to Defend Against the 6-Month V1 Rule:

• Configure your Anexo 24 software so that every V1 entry from another IMMEX plant is flagged with a 180-day expiration date (with automated 90-day, 120-day, and 150-day email alerts) unless your plant holds active OEA certification.
• Prioritize obtaining Authorized Economic Operator (OEA) certification under RGCE Rule 7.1.4 and Rule 7.3.3, Section XXV, which legally extends your IN and V1 permanence window to 36 months.

3. Does a Virtual Transfer (V1) Reset the 18-Month Clock Between Related Plants?

Watch out for a second statutory limitation under RGCE Rule 4.3.21 and Article 108 of the Customs Law:

• While transferring goods via a V1 pedimento to an unrelated customer starts the buyer’s permanence clock (6 months general; 36 months for OEA), you cannot bounce slow-moving inventory back and forth via V1 pedimentos between related companies or merely to reset an expiring 18-month clock without actual industrial transformation or a bona fide transaction.
• SAT’s AGACE auditors specifically query V1 transfers executed in months 16–18 of an IN pedimento’s life. If the goods never physically moved or underwent no transformation, SAT disqualifies the virtual transfer as a sham clock-reset and assesses omitted duties, VAT, and fines from the original IN entry date.

4. What Happens When the Clock Expires: Fines, VAT Surcharges & A3 Regularization

When raw materials (IN or V1) remain in Mexico past their 18-month, 12-month, or 6-month deadline, the financial exposure compounds across two separate laws:

A. Customs Law Exposure (Articles 182, 183, and Rule 2.5.2)

1. If You Catch the Expiration First (Spontaneous Regularization: Article 73 CFF & RGCE Rule 2.5.2):
   • Before SAT initiates an audit or sends a requirement notice, you can legally regularize the expired inventory into definitive import status by filing a Regularization Pedimento (Clave A3) under RGCE Rule 2.5.2.
   • You must pay:
     • General Import Duty (IGI) updated for Mexican inflation (INPC from the original entry date to the payment date under Article 17-A CFF), plus monthly interest surcharges (recargos at 1.47% per month under Article 21 CFF);
     • Customs Processing Fee (DTA);
     • 16% VAT (IVA) in cash (Forma de Pago 0), plus inflation updates and 1.47% monthly surcharges calculated from the original temporary import date; and
     • Comply with any applicable Non-Tariff Regulations (RRNA / NOMs).
   • Because the A3 filing is spontaneous (Article 73 CFF), you avoid the 70%–100% customs fines.
2. If You Return the Goods Late Before an Audit (Article 183, Section II, First Paragraph & Anexo 13 RGCE):
   • If you physically export (RT) the expired goods spontaneously after the deadline has passed, SAT assesses the inflation-adjusted Anexo 13 late-return fine of $3,020.00 to $4,560.00 MXN for every 15-day period (or fraction thereof) that elapsed past the deadline, capped at the total commercial value of the merchandise.
3. If SAT Discovers the Expired Inventory First During an Audit (Article 183, Section II, Second Paragraph & Article 178):
   • Once SAT serves an audit order, spontaneous regularization (Article 73 CFF) is blocked. SAT assesses omitted IGI, 16% VAT, inflation updates, 1.47% monthly surcharges, plus fines of 130% to 150% of the omitted IGI or 70% to 100% of the commercial value of the merchandise, and can place the physical expired stock under PAMA seizure.

B. SCCCyG (Anexo 30/31) Exposure

• Remember that an A3 regularization pedimento or a late RT export pedimento filed after the 18-month or 6-month deadline can be used in a Correction Discharge Report (Informe de Descargo de Corrección) in SCCCyG to clear the expired balance, provided you have paid the corresponding cash VAT, inflation updates, and surcharges.

5. Preventive Aging Protocol: The 12 / 15 / 17-Month Traffic Light System

Never wait until Month 18 (or Month 6 on a V1) to review open pedimento balances. Implement this automated monthly aging matrix in your Monthly IMMEX Compliance Committee: