Mexico's Senate voted 76 to 5, with 35 abstentions, on 10 December 2025 to raise import duties on 1,463 tariff lines from countries that have no free trade agreement with Mexico. The decree was published in the Diario Oficial de la Federacion on 29 December 2025 and took effect on 1 January 2026, with rates running from 5 to 50 percent depending on the product. Nine months later, the increase has already reshaped import volumes from Asia, and a second, narrower wave of antidumping duties on Chinese and Vietnamese steel took effect on 3 September 2026. This guide sets out what the decree actually covers, what still gets a manufacturer out of paying it, and what changed most recently, as of 30 September 2026.
The legal instrument and what it formalizes
The reform amends the Ley de los Impuestos Generales de Importacion y de Exportacion (LIGIE), Mexico's general import and export duties law. That distinction matters because Mexico had already raised many of these same rates through executive decrees in 2023 and 2024, justified at the time as temporary measures under presidential authority. The December 2025 reform consolidates those temporary increases into permanent legislation and extends coverage to sectors the earlier decrees had not touched: plastics, home appliances, aluminum, toys, furniture, leather goods, paper and cardboard, motorcycles, trailers, and glass. Textiles, footwear, and apparel were already covered by the earlier executive decrees, so for those sectors the reform mostly formalizes what importers were already paying.
Of the 1,463 affected lines, 316 previously carried no duty at all. The rest saw their rates increased. Unlike the earlier decrees, the new law carries no expiration date; it is indefinite unless Congress amends it again.
Which products, which rates
The heaviest rates sit in the automotive chapter. Finished passenger vehicles and light trucks from non-FTA countries, under HS codes such as 8703.22, 8703.32, 8704.21 and 8704.41, carry a 50 percent duty, matching what earlier executive decrees already applied to Chinese-made cars and now made permanent. Auto parts fare differently: components under HS chapters 8708, 8409, 8511 and 8512 sit at 7 to 36 percent, and a meaningful share of those lines had no duty before this reform. Reading the annex line by line against a typical automotive bill of material shows the detail sourcing teams miss most: a company confident its finished-vehicle exposure was the whole story can still find three or four previously duty-free component lines now taxed at double digits.
| Sector | Typical rate range | Status before the reform |
|---|---|---|
| Finished passenger vehicles, light trucks | 50 percent | Already at this rate under prior executive decrees; now permanent |
| Auto parts and components | 7 to 36 percent | Mixed: some new, some previously duty free |
| Textiles, apparel, footwear, leather goods | Up to 50 percent | Mostly formalizes 2023 to 2024 executive decrees |
| Steel, aluminum | Varies by tariff line | Newly expanded coverage |
| Plastics, appliances, toys, furniture, paper, glass, motorcycles, trailers | 5 to 50 percent, product specific | New under this reform |
One caveat on the rate range: the White and Case legal alert, which cites the Gazette notice directly, puts the reform at 5 to 50 percent. A separate manufacturing-advisory summary puts it at 10 to 50 percent. We could not resolve the gap from the documents available, so confirm the exact rate for each eight-digit tariff line rather than rely on either summary figure.
Who is covered, who is not
The tariffs apply only to imports from countries with which Mexico has no free trade agreement in force. The Secretaria de Economia frames the measure as general commercial policy rather than one aimed at any single country, but the countries most affected by trade volume are China, South Korea, India, Vietnam, Thailand, Brazil, Indonesia, Chinese Taipei, the United Arab Emirates and South Africa. Brazil needs a second look: Mexico and Brazil also trade under economic complementation agreements, and El Financiero describes the measure as applying to trade outside such agreements, so check whether your Brazilian lines fall under one. China opened a trade and investment barrier investigation into the measure; President Claudia Sheinbaum said publicly the increase is not aimed at China specifically. Imports from the United States and Canada under USMCA are unaffected, as are goods from Mexico's other free trade partners, a network covering more than 50 countries.
Where IMMEX and PROSEC change the math
For manufacturers operating under Mexico's IMMEX program, temporary imports of raw materials and components brought in for export manufacturing are not subject to the new tariff, as long as the finished good is exported within the program's timeframe. That is the biggest mitigation available to maquiladora-style operations sourcing from Asia.
It is not a full exemption once USMCA enters the picture. Under USMCA Article 2.5, the lesser of two duties rule, Mexico can only waive duty on non-originating inputs up to whatever amount the United States would charge on the finished product, as the manufacturing advisory firm Tetakawi explains it. Since USMCA-qualifying finished goods enter the US duty free, the amount Mexico can waive on a Chinese-origin input is then close to zero. On that reading, an IMMEX manufacturer that imports Chinese components, assembles a USMCA-qualifying product, and exports it duty free to the United States still owes Mexico the full LIGIE rate on those inputs at the Mexican border, despite holding valid IMMEX authorization. We did not find an official Mexican ruling that works this example through, so confirm your own case with a customs broker. PROSEC (Programas de Promocion Sectorial) and the related Eighth Rule mechanism can cut the applicable rate on specific qualifying inputs to 0 to 5 percent, which is why automotive, electronics, aerospace and medical device manufacturers with heavy PROSEC usage feel this reform less than a company without matching PROSEC coverage. Getting IMMEX, PROSEC and USMCA origin paperwork right at once is a documentation problem as much as a tariff one; our guide to Mexico's parallel customs law reform covers what changed in broker liability and entry documentation over the same period, a distinct legal track from the tariff schedule.
What the numbers show, eight months in
Lining up trade data for January through May 2026 against the same months in 2025 gives the first measurable read on the reform's effect. Imports on the 1,463 taxed lines fell 23.2 percent overall, from about 15,383 million dollars to 11,808 million dollars. China-origin imports on those same lines fell further, down 28.4 percent, from about 10,099 million to 7,228 million dollars. Light vehicles by value dropped 29.7 percent, and trailers, the steepest decline of any category tracked, fell 54.5 percent.
| Indicator, Jan to May | 2025, US$ million | 2026, US$ million | Change |
|---|---|---|---|
| Imports on the 1,463 taxed lines, total | 15,383 | 11,808 | minus 23.2 percent |
| Same lines, China origin only | 10,099 | 7,228 | minus 28.4 percent |
| Light vehicles, by value | not reported separately | down 1,180 | minus 29.7 percent |
| Trailers | not reported separately | not reported separately | minus 54.5 percent |
A drop in recorded imports is not the same as demand disappearing. Some of that volume shifted origin to FTA-covered suppliers, some absorbed the tariff and continued at a higher landed cost, and some moved into different customs treatments, including IMMEX temporary import status that keeps the goods off the taxed-import statistics until they either export out or convert to permanent import. We could not find a public breakdown separating those three outcomes, so treat the volume drop as directional evidence of the tariff working as intended rather than a precise substitution count.
The August rumor, and what actually changed
On 18 August 2026, press reports circulated that Mexico was weighing a fresh round of tariff increases on Chinese goods, timed to the ongoing USMCA review. Mexico's Economy Ministry told the financial daily El Financiero the same day that there is currently no plan or concrete proposal for new tariff adjustments, though it confirmed it continues to review antidumping allegations case by case. The distinction matters. The USMCA joint review, whose formal Article 34.7 review date fell on 1 July 2026, is a negotiation about rules of origin and regional content between the US, Mexico and Canada. Mexico's decision to tax non-FTA imports from Asia is a unilateral trade-policy choice that does not depend on that negotiation, even though both get discussed in the same news cycle.
The antidumping track is where the real September news sits. On 3 September 2026, Mexico's Economy Ministry set final antidumping duties of 24.5 percent on Chinese hot-rolled steel and 16.3 percent on Vietnamese hot-rolled steel, stacked on the existing 15 percent MFN rate on 19 tariff lines. Those rates replace provisional duties of 28.7 and 18.5 percent applied since March 2026, following a complaint Ternium Mexico filed in March 2025. A separate final determination on aluminum hollow profiles from the US and China followed on 4 September. Neither is part of the January 2026 general decree; both are product-specific remedy cases stacked on whatever the general LIGIE rate already is for that line. A general decree did follow the January reform, though: on 23 April 2026 Mexico published a second amendment to the LIGIE tariff schedule, adding 185 more tariff lines at rates of 5 to 35 percent across sectors the December 2025 law had not reached, including cosmetics inputs, graphic arts products, bicycles, additional auto parts, wind turbine components, and trailers not used for passenger transport, again exempting FTA partners. As of 30 September 2026, no further general tariff decree has been published beyond that April expansion.
Effects on Pacific freight flows
Fewer taxed containers moving through Manzanillo and Lazaro Cardenas from China does not mean less total Pacific volume. Nearshoring component imports for USMCA-qualifying manufacturing have kept container demand elevated even as light vehicles and trailers, the categories hit hardest by the tariff, show the steepest declines. Weighing the import-volume data against sourcing shifts, we read this as a rerouting effect more than a demand collapse: shippers moving away from non-FTA Asian suppliers are also changing which Pacific ocean lanes carry the volume, since a shift from China to Vietnam or a South American FTA partner changes both port of loading and transit time. Port-side congestion at Mexico's main Pacific gateway is a separate story, covered in our Manzanillo congestion and gateway alternatives guide; the tariff reform is one input into that picture, not its cause.
A practical checklist
We built this around the two failure modes that show up most in importer paperwork: missing a tariff line inside a sector that looks exempt, and assuming an IMMEX authorization covers more than it does once USMCA exports enter the calculation.
- Look up every eight-digit tariff line in your import portfolio against both the December 2025 decree's annex and the April 2026 expansion decree; do not rely on a sector-level summary, since some categories carry mixed treatment line by line.
- Rebuild the landed-cost model for each affected line, including the base LIGIE rate, any applicable antidumping or countervailing duty layered on top, and freight and dwell-time costs that shift with routing changes.
- Confirm origin documentation is airtight if you claim USMCA or another FTA preference; a certificate that does not hold up under review leaves you exposed to the full non-FTA rate retroactively.
- If you operate under IMMEX, verify whether your finished product qualifies for USMCA preference on export, and run the Article 2.5 lesser of two duties calculation on every non-FTA input before assuming the IMMEX exemption applies in full.
- Check whether a PROSEC or Eighth Rule registration exists, or could be obtained, for your sector; this is the main documented mechanism for cutting the effective rate on qualifying non-FTA inputs to near zero.
- Track the Gazette for antidumping resolutions specific to your product, separate from the general LIGIE decree; steel, and specifically hot-rolled coil and plate, is the most recent example of a stacked, product-specific duty.
- Watch the USMCA joint review timeline for any provisions on non-market inputs or regional content that could change how Chinese-origin components are treated inside a USMCA-qualifying supply chain, even though the review itself is a separate track from Mexico's own tariff decree.
Common questions
When did Mexico's new tariffs take effect? 1 January 2026, under a decree published in the Diario Oficial de la Federacion on 29 December 2025.
How many products are affected? 1,463 tariff lines, of which 316 previously carried no duty at all.
What rates apply? Between 5 and 50 percent, product specific; finished passenger vehicles and light trucks sit at the 50 percent ceiling, while many auto parts run between 7 and 36 percent.
Does IMMEX exempt my imports entirely? Only for temporary imports later exported. If the finished good also exports under USMCA preference, Article 2.5 claws back most of that exemption on non-FTA inputs unless PROSEC or Eighth Rule coverage applies.
Did Mexico raise tariffs again on China in August 2026? No. The Economy Ministry told local press on 18 August 2026 that no new general tariff plan exists, while confirming case-by-case antidumping reviews.
What changed most recently? A separate, product-specific antidumping duty on Chinese and Vietnamese hot-rolled steel took effect 3 September 2026, stacked on top of the general tariff and MFN rate on those 19 lines.
Sources: Secretaria de Economia press communication (Comunicado 123, 30 December 2025); Diario Oficial de la Federacion decree, referenced via White and Case LLP trade alert (29 December 2025); White and Case LLP trade alert on the April 2026 expansion decree (1 May 2026); Associated Press wire report on the Senate vote (11 December 2025); Tetakawi manufacturing-advisory analysis, updated 22 September 2026; El Financiero trade-data reporting (21 July 2026) and Economy Ministry statement reporting (18 August 2026); HS Code Match News report on Mexico's September 2026 antidumping resolution, citing the Federation Gazette. Position stated as of 30 September 2026.