Customs clearance is a black box for most importers. A container reaches Manzanillo, days go by, and suddenly you’re told it’s released or it’s been held — but you rarely get told what happened in between. Here’s the full flow, with typical timelines and the points where 9 out of 10 operations get stuck.
Step 0 — Before arrival: document pre-validation
Clearance starts before the ship touches land. When the shipment leaves origin, the forwarder or your importer-of-record should already have:
- Commercial invoice with value, description, weight, and country of origin.
- Packing list with package counts, dimensions, and gross/net weight.
- Bill of Lading (ocean BL), Air Waybill (AWB), or land carta porte — the transport document proving the shipment.
- Certificate of origin if a trade agreement applies (T-MEC/USMCA, EU-Mexico FTA, etc.).
- Special certificates: NOM, phytosanitary, sanitary, COFEPRIS, depending on the product.
- Cargo manifest transmitted by the carrier to the SAT.
Typical timing: 5-10 days before arrival. When paperwork arrives late, the container sits at port racking up demurrage.
Step 1 — Arrival and unloading
The ship docks at port (Manzanillo, Lázaro Cárdenas, Veracruz, Altamira). The container moves to the port’s bonded yard under customs control. The “free” storage days begin here (typically 5-7 free days; after that it’s charged daily and gets expensive fast).
Typical timing: 1-3 days from arrival to yard availability.
Step 2 — Tariff classification and entry preparation
The customs broker (a figure legally required for most commercial imports in Mexico) takes the documentation and:
- Classifies each item under its tariff code (8 digits) and NICO (2 extra digits since 2020). This is where the most expensive mistakes are made.
- Calculates duties: IGI (general import tax), VAT (16%), DTA (customs processing fee, roughly $439 MXN per entry or 8 per thousand depending on regime), and where applicable IEPS or compensatory quotas.
- Captures the pedimento (customs entry) in the SAT system (SAAI / VUCEM).
- Requests payment of duties from the importer or the importer-of-record.
Typical timing: 1-2 days if paperwork is clean. A week or more if classification is doubtful or documentation is missing.
Step 3 — Payment of duties
You pay duties at an authorized bank or by SPEI transfer. Until that payment is registered in VUCEM, the random selection mechanism cannot be triggered.
Typical timing: same day if you pay early.
Step 4 — Random selection mechanism (the “fiscal traffic light”)
This is the key moment. The SAT system automatically decides one of two outcomes:
- Green (~85% of entries): goods pass without physical inspection. They leave the bonded yard directly.
- Red (~15%): customs inspection. A verifier opens the container, compares against the entry, checks labels, classification, marks, quantities.
In clean operations, the inspection is resolved the same day. If inconsistencies are found (bad labeling, undeclared merchandise, suspicious value), it can escalate to PAMA proceedings or precautionary seizure.
Step 5 — Customs inspection (only if it hit red)
The verifier checks:
- That physical quantity matches the pedimento.
- That the technical description corresponds to the declared tariff code.
- That NOM labels are present and compliant.
- That brands, models, and serial numbers match the invoice.
- Physical origin: marks of origin stamped or labeled correctly.
Typical timing: half a day to a day if everything is in order. With a minor observation (re-labeling, clarification), a couple of days. If PAMA, weeks or months.
Step 6 — Release and exit from the bonded yard
When the entry is modulated (green direct or red approved), the customs broker issues the release pass. With it, the ground carrier enters the yard, picks up the container, and heads to destination.
Typical timing: same day.
Step 7 — Ground transport to final destination
The land carrier moves the container to your warehouse, a bonded warehouse, or a distribution center. In Mexico, all road transport requires a carta porte CFDI (version 3.1, the only valid one since July 2024).
Typical timing from Manzanillo: 1-2 days to the Bajío (Querétaro, San Luis Potosí, Aguascalientes), 1 day to Mexico City, 2-3 days to the northeast.
Typical end-to-end timeline (clean operation)
| Stage | Days |
|---|---|
| Arrival at port + unloading | 1-3 |
| Documentation + entry | 1-2 |
| Payment of duties | <1 |
| Selection + (red) inspection | 1-2 |
| Exit from yard + ground transport | 1-2 |
| Total ocean Asia → warehouse Mexico | 6-10 days from port arrival |
Added to ocean transit (28-40 days Shanghai → Manzanillo), total door-to-door is 35-50 days under normal conditions.
Where 80% of clearances get stuck
1. Incomplete or inconsistent documentation
The invoice says “wireless headphones,” the BL says “electronic accessories,” the packing list says “consumer electronics.” The system reads it as inconsistency. How to prevent it: cross-check documents before shipping, not after.
2. Misassigned tariff code
You want to pay 0% and the correct code pays 15%. If the verifier catches it, reclassification follows, you pay the difference + adjustment + surcharges + possible fine. How to prevent it: classification verified with a technical opinion when the product is new or the code is uncertain.
3. Unfulfilled or missing NOM
Label only in English, missing NOM-003 electrical certificate, FDA-style nutritional table instead of NOM-051. How to prevent it: map applicable NOMs to the product before closing the purchase (see our NOMs post).
4. Suspicious customs value
You declare a value well below the estimated price the SAT has in its database. They demand a customs account guarantee or the entry gets stuck. How to prevent it: document the price with the evidence chain (purchase order, supplier communication, bank transfers).
5. Importer registry with observations
Your tax ID is suspended in the sectoral registry, or you have some inconsistency with your SAT compliance opinion. No one warns you — you find out when the entry fails. How to prevent it: verify registry status before every shipment, not at the end.
Most common customs regimes
Not all operations go through definitive import. Quick reference:
| Regime | What it’s for |
|---|---|
| Definitive (A1) | Standard import, goods stay in national territory. |
| Temporary IMMEX | Temporary import for transformation and re-export. |
| Fiscal deposit | Goods in a general bonded warehouse without paying duties until withdrawal. |
| Strategic bonded facility (RFE) | Processing inside a fiscal zone without nationalization. |
| Transit | Goods cross Mexico toward another country. |
Each has its own entry type, requirements, and costs.
At TradeWay
We’re an importer-of-record (comercializadora) and operate directly with customs brokers licensed at Manzanillo, Lázaro Cárdenas, Veracruz, Nuevo Laredo, and Mexico City Airport (AICM). We pre-validate all documentation before arrival so your goods don’t get stuck in the yard. If you have an upcoming operation or want a second opinion on a clearance already in motion, contact us — in under 24 business hours we review your case and tell you what can be improved.
