USMCA for Mexican Goods — Why It Works and When It Doesn't
For the typical Mexican manufacturer exporting to the US, the math is simple: goods meeting USMCA origin rules enter at zero duty. No VAT. No federal sales tax at the border. The total tariff line reads $0.00. Compare that to European importers who layer VAT on duty, or Canadian importers who add GST plus provincial tax — the US is structurally the cheapest major economy to import into, and USMCA makes it cheaper still for Mexican goods.
But CBP has grown more aggressive about verifying Mexican origin claims since 2023, driven by three things: the surge in Chinese investment in Mexican factories, rapid growth of nearshoring assembly operations using Chinese components, and the US government's concern about transshipment to evade Section 301 tariffs. A Mexican commercial invoice isn't enough — CBP wants to see where the value was created. For the reverse-direction math, see our China to Mexico IMMEX guide — Mexico's import regime is materially tougher, with 16% IVA and higher MFN rates.
Products That Dominate Mexico→US Trade
| Category | Duty Under USMCA | What to Watch |
|---|---|---|
| Passenger vehicles & light trucks | 0% | 75% RVC is the highest bar in USMCA. Must meet RVC, labor value content (40–45% at $16+/hr), and 70% North American steel/aluminum purchasing. Major OEMs clear these. Smaller assemblers using imported drivetrains may not — duty is 2.5% of vehicle value on a miss. |
| Auto parts | 0% | 65% RVC for principal parts, 75% for core (engine, transmission, chassis). Aftermarket parts made from imported steel face tighter RVC math. |
| Electronics assembly | 0–2.5% | Fastest-growing and most-scrutinized category. TVs from Tijuana, circuit boards from Juárez, consumer electronics from Reynosa. Many clear USMCA via tariff shift — but CBP audits this category aggressively. Documentation of the transformation process is essential. |
| Medical devices | 0% | Tijuana and Mexicali are major device hubs — surgical instruments, implants, disposables. Most qualify for zero under USMCA or Chapter 90 duty-free provisions. FDA registration is the bigger compliance lift. |
| Fresh produce | 0% (mostly) | Mexico supplies half of US fresh fruit imports, two-thirds of fresh vegetables. Most produce enters duty-free under USMCA. A few items have seasonal duties — certain tomatoes during US harvest windows. USDA/AMS publishes the calendar annually. Real cost is inspection, cold chain, and border wait time. |
Freight costs for Mexican goods are lower than for Asian imports — trucking Monterrey→Dallas costs a fraction of Shanghai→LA container freight. But lower freight doesn't eliminate the need to properly calculate CIF. Our landed cost calculator handles CIF→duty→total regardless of origin.
The IMMEX Connection — How the Maquiladora Program Affects US Duty
IMMEX (Industria Manufacturera, Maquiladora y de Servicios de Exportación) allows duty-free import of raw materials and components into Mexico for processing and re-export. From the US customs perspective, IMMEX itself doesn't change the duty calculation — but it matters for two reasons.
First, the country-of-origin question. An IMMEX factory imports Chinese steel, stamps it into auto body panels in Sonora, ships to Michigan. Has the origin changed? Under USMCA's tariff shift rule: yes — steel (Chapter 72) became auto parts (Chapter 87), a different chapter. But if the same factory cuts the steel to length — same chapter, no substantial transformation — origin remains China. CBP's "substantial transformation" test asks whether the manufacturing process changed the name, character, or use. Stamping: yes. Cutting: no.
Second, the Section 301 overlay. This is where the nearshoring model faces its biggest risk. Chinese company sets up assembly in Monterrey, imports Chinese components under IMMEX, ships to US claiming USMCA preference. If CBP determines insufficient transformation — goods are still Chinese-origin — two things happen: the USMCA claim is denied and Section 301 tariffs (7.5–25%) apply. Several 2025 enforcement actions targeted exactly this pattern in electronics and solar. Get a CBP binding ruling ($300, 30-90 days) before scaling volume — it's the cheapest insurance against post-entry audit risk.
Fresh Produce — What Happens When Tomatoes Hit the Border
Seasonal duties. A few produce categories have time-limited tariffs during US harvest windows. The calendar is USDA/AMS-published and commodity-specific. Most Mexican shippers know their crop's calendar; new importers should confirm the seasonal rate for their commodity and entry date through their broker.
USDA inspection. Separate from CBP, USDA inspects virtually all fresh produce at the border. Not a tariff — an inspection fee — but adds cost. Inspectors work at all major crossings (Laredo, Nogales, Pharr, Otay Mesa). Weekend arrivals may sit until weekday shifts.
The Tomato Suspension Agreement. Since 1996, US and Mexican growers have operated under agreements setting minimum reference prices for Mexican tomatoes. The 2019 agreement remains in effect. Not a duty — a trade remedy mechanism — but effectively a price floor. Mexican tomato exporters must sign the agreement. Avocados: no suspension agreement, no seasonal duties, zero USMCA, constraint is USDA phytosanitary certification (Michoacán is certified).
Nearshoring Compliance — Practical Tips
- Don't use Mexican HS codes on US entries. TIGIE and HTS harmonize for the first six digits, often diverge after. Your US broker confirms the HTS code.
- Don't undervalue to stay under $800. CBP valuation enforcement is aggressive. Penalties: 2–8× lost duty.
- IMMEX re-export ≠ USMCA origin. Different legal standards. Satisfying IMMEX doesn't automatically satisfy USMCA.
- File CBP Form 5106 before the first truck. Importer number is free — get it before the truck's at the Laredo station. For the full US clearance procedure: US import customs guide.
Related Corridors & Guides
Frequently Asked Questions
Do Mexican goods pay US customs duty?
Most do not. USMCA-qualifying goods enter at zero duty — vehicles, auto parts, electronics, medical devices, produce. Exceptions: products with predominantly non-North American content not substantially transformed in Mexico, steel/aluminum that triggers Section 232 quotas (currently exempted), and a small number of seasonal agricultural items.
Does the US charge sales tax on Mexican imports?
No. The US has no federal VAT. CBP doesn't collect state sales tax. This is a major structural difference from importing into Mexico (16% IVA), Canada (GST + provincial), the UK (20% VAT), or the EU. Landed cost = CIF value + any applicable duty. If duty is zero under USMCA, landed cost = CIF.
What's the IMMEX program and does it affect US duty?
IMMEX allows duty-free import of materials into Mexico for processing and re-export. From CBP's perspective, IMMEX does not determine USMCA eligibility — CBP evaluates origin independently. Goods produced under IMMEX that meet USMCA rules enter the US duty-free. Those that don't pay the applicable MFN rate. The IMMEX/USMCA interaction is one of the most active CBP enforcement areas.
Can I ship from Mexico to US customers without paying customs?
Yes, in two scenarios. Scenario one: goods qualify for USMCA — zero duty regardless of value. Scenario two: shipment is $800 or less — clears under Section 321 de minimis, no duty, no formal entry, no bond, regardless of origin. The $800 threshold is per consignee per day. For B2C e-commerce from Mexico to US customers, de minimis makes small-package clearance essentially friction-free.