Once your customs entry (pedimento) is paid and the goods are presented at customs, the automated selection mechanism kicks in — the famous red/green light (semáforo). Green: your cargo keeps moving. Red: it goes to a customs examination, a physical and documentary review before release.
What the “light” actually is
It isn’t a lottery, even though there’s a random component. It’s a risk-management system: it cross-references your profile as an importer, the type of goods, the origin, the declared value, the port of entry and the operation’s history. Certain profiles pull red far more often than others — and that part you can influence.
What they check in the exam
- That the goods match what was declared: description, quantity, weight, brands and models.
- That the tariff classification is right for what’s actually in the box.
- That the declared value holds together and shows no signs of undervaluation.
- That the non-tariff regulations are met: NOMs, labeling, permits.
- That the declared origin is backed up if preferential treatment was claimed.
How long does it take, and what does it cost?
An exam with no findings usually clears in 1 to 3 business days. The cost isn’t the review itself: it’s the cargo handling — unloading, inspection and reloading — plus the storage for the extra days and, when it applies, the detention on a container that didn’t make it back in time. Budget that cushion from day one.
If they find an irregularity
Depending on severity, it can range from a correction of the customs entry with payment of the difference, up to a PAMA (Mexico’s formal customs enforcement proceeding) with precautionary seizure of the goods. The difference between a scare and a serious problem almost always comes down to the file: if your documents support what you declared, it gets resolved.
How to lower your odds of a red
- A clean track record. A recurring importer with no incidents builds a low-risk profile. It’s earned over time, one operation at a time.
- Precise descriptions. “Plastic articles” is an invitation to be inspected. Full description, brand, model and composition.
- Consistent, supported value. If your value sits well below your tariff code’s reference prices, expect attention. Your value declaration and your proof of payment are the defense.
- Correct, stable classification. Switching tariff codes between shipments of the same product draws attention.
- Pre-clearance inspection at origin or at the terminal. Physically checking the cargo before clearance lets you fix discrepancies before you declare them.
- AEO / NEEC certification. For importers with volume, Authorized Economic Operator status means fewer inspections and real facilitation. Worth evaluating.
The thing to understand: the exam isn’t a punishment — it’s a check that what you declared is true. If your file is in order, a red is time and money: annoying, but manageable. If it isn’t, a red is where the problem gets discovered.
Pulled a red and not sure what comes next? Write to us — we handle customs exams every day and know what can be fixed on the spot and what needs a different strategy.