Mexico IMMEX Operations for China Manufacturers

Once a Chinese manufacturer decides to establish production in Mexico, the hardest question is usually no longer whether it can obtain an IMMEX program. The real challenge is designing production, imports, warehousing, subcontracting, domestic sales, exports, customs, finance and HQ control as one sustainable operating model.

For China HQ, IMMEX is better understood as a manufacturing operating framework than as a stand-alone tax incentive. Whether the program remains usable over time depends on whether the business facts described in the authorization, the plant's actual processes, the temporary-import lifecycle, inventory controls and recurring compliance continue to match.

ASCG Pacific's China → Mexico Expansion work starts from that operating model: define what the Mexican entity actually does and how the supply chain works, then connect IMMEX, customs, tax, accounting and group reporting around the same facts.

Core point: for a Chinese manufacturer, the riskiest IMMEX situation is often not “we do not have the program yet.” It is “we have the program, but the factory, suppliers, warehouses, ERP and customs process have gradually become a different operating model from the one that was authorized.”

What does IMMEX actually solve? It is not a pass that makes every import tax-free

Mexico's Secretaría de Economía describes IMMEX as an export-promotion instrument that allows qualifying Mexican legal entities to temporarily import certain goods for export manufacturing or services, with the applicable import-tax treatment deferred under the relevant rules.

China HQ should therefore separate three questions from the beginning:

Does the Mexican company hold an IMMEX program?
Can a specific item be imported temporarily under the applicable rules?
What is the actual IGI, IVA, IEPS or other tax treatment of that temporary import?

Having IMMEX does not automatically answer questions two and three.

Certain sensitive goods can be subject to additional requirements. IVA/IEPS credit or guarantee treatment may also depend on whether the company has the relevant IVA/IEPS certification or operates through an accepted guarantee mechanism. For the China HQ plant budget, those distinctions can affect ramp-up cash flow just as much as customs compliance.

Before applying for IMMEX, map the plant's real operating model

An Industrial IMMEX application requires information about the production process, project, expected imports and exports, capacity, materials and waste. That is a strong indication that the application should not be prepared by customs alone.

Before filing, management should define at least:

whether the Mexican entity performs manufacturing, assembly, repair, services or another function;
which group company supplies raw materials, machinery, tooling or technology;
which entity owns raw material, WIP and finished goods;
whether output will be exported to the United States, Canada or other markets, or also sold in Mexico;
which processes remain in the main plant and which are performed by a submanufacturer / submaquila provider;
whether the project uses third-party warehouses, external processing sites or multiple plant locations;
which entity is responsible for imports, exports, customer contracts and cash collection; and
how the ERP, customs system and China HQ reporting identify the same goods.

Those answers influence IMMEX scope, registered locations, inventory, transfer operations, intercompany transactions and financial reporting.

If the authorization describes a fully integrated manufacturing process in the Mexican plant, but after launch critical processes migrate to third-party locations that were never incorporated into the model, the issue is no longer simply an operational change. The authorized model and actual model have begun to diverge.

Industrial, outsourcing and submanufacturing are not interchangeable concepts

Chinese manufacturers in Mexico frequently use local suppliers for plating, painting, heat treatment, injection molding, assembly, packaging or other specialized processes.

But “a third party participates in production” can describe several different legal and customs structures.

VUCEM and Secretaría de Economía provide different IMMEX authorization, expansion and registration paths, including Industrial, Terciarización and registration of submanufacturers. The facts, controls and responsibilities behind those structures are not the same.

Before signing an outsourcing agreement, the company should determine at least:

whether the third party is an ordinary Mexican supplier or a submanufacturer that will physically handle temporarily imported goods;
whether legal ownership of the goods changes;
how temporarily imported goods move to the third-party site;
whether that site must be registered within the relevant program/customs framework;
who owns inventory and traceability responsibility;
how material usage, scrap, returns and finished goods will be recorded; and
whether the structure triggers monthly, semiannual or other notices or reports.

Under the 2026 customs framework, submaquila operations include a monthly transfer notice mechanism covering qualifying transfers performed during the preceding month. Submanufacturing therefore should not be managed only by procurement through a purchase order.

Every temporary import needs a lawful end state

One of the most important concepts for HQ finance is that a temporary import is not an ordinary purchase receipt.

The basic IMMEX customs logic is that goods enter Mexico temporarily for an authorized manufacturing, transformation, repair or related export activity and must, within the applicable period, be returned abroad or lawfully moved into another permitted customs outcome.

A shipment from China cannot simply disappear through ERP consumption and be treated as finished from a customs perspective.

Customs still needs to know what ultimately happened to the goods, for example:

they were exported as part of finished goods;
they were returned abroad in the same condition;
they were transferred to another qualifying company;
they were changed to definitive import status;
scrap or waste was handled under the applicable rules; or
another lawful customs outcome completed the lifecycle.

If the applicable stay period expires without a lawful treatment, the issue can escalate from an inventory variance into a customs-compliance exposure.

That is why customs aging should be a management metric, not merely a total inventory balance.

If the Mexico plant may sell locally, design the domestic-sales path in advance

Many nearshoring projects begin with a simple assumption: “the Mexican factory will export 100% of its output to the United States.” Two years later, a Mexican OEM or tier supplier wants to buy locally.

That should not be treated as “the same IMMEX inventory, just with a Mexican invoice.”

If temporarily imported foreign materials, or goods containing them, will ultimately enter the Mexican market, the company may need to evaluate, depending on the facts:

a change of customs regime;
applicable IGI, IVA, updates or other duties/taxes;
non-tariff regulations;
customs value and tariff classification; and
synchronized status changes in ERP, Anexo 24 and financial costing.

The 2026 customs rules contain specific procedures for temporary-to-definitive changes and, in qualifying cases, may allow treaty tariff treatment when the necessary conditions and evidence are satisfied.

China HQ should therefore separate from day one:

the export-production flow and the Mexico domestic-sales flow.

If local sales are a realistic future possibility, contracts and systems should already contain that path rather than allowing the customs broker to invent it once the first customer order arrives.

Transfer operations can make the supply chain more efficient, but they need their own documentation logic

An important tool within the Mexican IMMEX ecosystem is the qualifying transfer or virtual operation.

In applicable cases, goods can move between IMMEX or other qualifying parties under prescribed customs procedures without requiring a traditional physical export and re-import for every step.

This can be valuable in automotive, electronics, appliances and other multi-tier supply chains where a Chinese group's Mexican plant sends intermediate goods to another IMMEX supplier for further processing.

But a virtual transfer is not simply an ERP stock transfer. The company still needs to control:

the corresponding pedimento/customs record;
CFDI or other supporting transfer documents where applicable;
consistent quantities between transferor and transferee;
correct discharge or assumption of temporary-import balances;
tariff classification and value consistency; and
timing and system records on both sides.

SAT has specific rules and procedures for transfer operations. If a Chinese group plans a multi-plant or multi-supplier network in Mexico, the transfer model should be designed during supply-chain planning rather than selected transaction by transaction by the broker.

Anexo 24 is the IMMEX lifecycle ledger, not another warehouse system

The 2026 Anexo 24 requires covered companies to maintain an automated inventory-control system capable of supporting the traceability of temporarily imported goods, including entries, usage, exports/other exits, balances and material consumption, and of producing the information required by the customs rules.

For China HQ, it can be understood as a customs lifecycle ledger:

For any temporary import, the company should be able to explain through which pedimento it entered, which part number it relates to, where it is located, which production process consumed it, how much was consumed and how the goods were ultimately returned, discharged or otherwise lawfully resolved.

That is not exactly the same objective as SAP, Oracle, Kingdee, Yonyou or another ERP.

ERP is primarily designed for production and finance. Anexo 24 focuses on temporary-import traceability. The right model is not one system instead of the other, but a mapping across:

part number;
unit of measure;
BOM/material usage;
customs entry;
warehouse/location;
production movement;
scrap;
export / transfer / change of regime; and
inventory balance.

In 2026, use the current Anexo 30 / SCCCyG name rather than treating it as “Anexo 31”

Many software vendors, advisers and internal SOPs still use the historical label “Anexo 31.”

Under RGCE 2026, however, the Sistema de Control de Cuentas de Créditos y Garantías (SCCCyG) is contained in Anexo 30.

SCCCyG is mainly used to administer credits and guaranteed amounts related to applicable IVA/IEPS certification or guarantee regimes. It does not have the same objective as Anexo 24, although both depend heavily on the same underlying customs data.

A company can therefore find itself with:

correct ERP quantities;
a different Anexo 24 balance; and
yet another SCCCyG credit/guarantee discharge amount.

A mature control environment does not consist of installing three pieces of software. It defines who owns the reconciliations, when they are reviewed and what variance triggers escalation to finance or customs management.

Chinese suppliers, Mexican suppliers and related-party purchases should follow different control tracks

A China → Mexico plant quickly combines at least three sourcing categories.

1. Materials imported from China or elsewhere in Asia

Key issues include tariff classification, customs value, temporary vs definitive import status, stay periods, transportation, ownership and intercompany pricing.

2. Mexican domestic sourcing

These purchases normally do not follow the same temporary-import lifecycle, but they still affect the BOM, costing, supplier tax documentation and product-origin analysis.

3. Related-party transactions

In addition to procurement and customs, they may also enter transfer-pricing, intercompany AP/AR, FX, financing or service-fee processes.

If the ERP uses a single generic supplier category, management loses visibility into the customs, tax and ownership attributes behind inventory.

Vendor master and material master data should include enough tags to allow month-end reporting by source, ownership and customs status.

“Chinese inputs + manufacturing in Mexico” does not automatically produce USMCA origin

IMMEX and USMCA are different systems.

IMMEX governs the temporary-import/export-manufacturing framework. USMCA preferential treatment depends on whether the product satisfies the applicable rules of origin.

A Chinese manufacturer therefore cannot conclude that an item qualifies for USMCA simply because substantial production occurred in Mexico, the goods are labeled Made in Mexico or the plant operates under IMMEX.

The company still needs a product-level analysis of tariff classification, tariff shift, regional value content, product-specific rules and non-originating materials.

This matters particularly in Chinese supply chains because engineering teams may change a China/Asia supplier based on price or capacity without notifying the team responsible for origin analysis.

Supplier-change management should therefore trigger, where relevant:

BOM review;
tariff/classification review;
cost update;
Anexo 24 mapping review; and
USMCA origin reassessment.

IMMEX is not a one-time project: program maintenance affects the ability to keep operating

After authorization, the company must maintain the conditions of the program.

Secretaría de Economía requires program holders to file the Reporte Anual de Operaciones de Comercio Exterior (RAOCE) for the prior year, generally by the last business day of May.

The 2026 suspension process again demonstrated that companies that fail to file the annual report can be suspended and, if they do not cure the issue within the applicable correction period, may face cancellation later in the year.

The framework also requires companies to maintain core conditions such as a valid e.firma, active RFC, registered operating locations and the applicable tax-compliance status.

HQ should therefore maintain a permanent compliance calendar covering items such as:

RAOCE;
RFC / e.firma / tax-compliance status;
changes in plants, warehouses and other registered locations;
shareholder/corporate changes when they trigger a notice;
changes in submanufacturers or outsourced locations;
products, services or sensitive-goods expansions where applicable;
Anexo 24 reconciliations;
IVA/IEPS certification or guarantee maintenance; and
customs-aging exceptions.

The annual export condition belongs on a management dashboard, not in a May-only compliance file

The IMMEX framework maintains an operating condition that group management can easily overlook: in general, the program holder must achieve annual foreign sales above USD 500,000 or invoice exports equal to at least 10% of total invoicing, subject to the applicable rules, including treatment of the authorization year and pre-operational periods.

For a large manufacturing project, the threshold itself is often not difficult. The risk appears when launch is delayed, equipment commissioning takes longer than expected, customer SOP moves, or the domestic-sales mix increases unexpectedly and no one is monitoring the program condition.

The plant ramp-up dashboard can therefore include:

YTD export sales;
total invoicing;
export ratio;
pre-operational status; and
RAOCE forecast.

This turns IMMEX maintenance from a once-a-year filing exercise into an operating metric visible throughout the year.

Four common operating scenarios for Chinese manufacturers

Scenario A: China ships materials, Mexico assembles and exports to the United States

This is a classic nearshoring model.

The key control is complete traceability from temporary import → receipt → BOM consumption → finished goods → export/discharge, while ensuring that intercompany price, customs value, USMCA origin and group financial cost are not four contradictory versions of the same transaction.

Scenario B: a critical process is performed by a Mexican submanufacturer

Examples include plating, painting, heat treatment or specialized assembly.

External location, goods transfer, submaquila notice, material loss and returned goods all need to enter the IMMEX control framework. A procurement agreement by itself does not replace customs traceability.

Scenario C: the Mexico plant exports and also sells domestically

The systems must distinguish which materials and products remain on the export/temporary-import path and which need to move into the domestic-sales/change-of-regime path.

If the same SKU can serve both order types and the systems do not segregate customs status, high-volume operations can quickly create inventory balances that are difficult to explain.

Scenario D: the group uses multiple Mexican entities or IMMEX suppliers

Transfer/virtual operations can connect multiple plants and suppliers efficiently.

The trade-off is a higher need for synchronization: transaction timing, pedimentos, CFDI/supporting documents, quantities and both parties' inventory systems need to agree. Otherwise one party may discharge a balance that the other party never properly assumes.

A 14-point readiness check for China HQ before the first temporary import

Does the Mexican entity's IMMEX modality match the actual operating model?
Does the production process described in the authorization match the plant SOP?
Are all plants, warehouses and relevant external locations properly incorporated?
Which suppliers will physically handle temporarily imported goods, and are any of them submanufacturing arrangements?
How will temporary-import stay periods and customs aging be monitored?
When a domestic sale occurs, who triggers the change-of-regime review?
Who reconciles the transferor, transferee and broker records for virtual transfers?
Are ERP part numbers, UOMs and BOMs mapped to Anexo 24?
How are scrap, rework, replacement materials and engineering changes reflected?
Is the actual IVA/IEPS certification or guarantee path clear?
Is there an owner and reconciliation calendar for SCCCyG / Anexo 30?
Do China/Asia supplier changes trigger customs and origin review?
Is the USD 500k / 10% annual export condition visible in the management dashboard?
Are RAOCE, registered locations, e.firma, RFC and program modifications assigned to named owners?

If only the customs broker can answer these questions while the Mexico plant controller and China HQ finance cannot, IMMEX is still being treated as a customs project rather than as part of the operating model.

A more robust China manufacturer → Mexico IMMEX implementation sequence

Phase 1: Business + supply-chain map

Define customers, material sources, production steps, ownership, export destinations, domestic-sales potential, outsourcing and entity roles.

Phase 2: IMMEX authorization design

Select a modality that matches the facts, prepare the production process, capacity, materials, locations and export project, and identify sensitive goods or special conditions early.

Phase 3: Customs architecture

Define broker responsibilities, tariff classification, the temporary-import lifecycle, transfer rules, submanufacturing flow, domestic-sales path and customs-aging controls.

Phase 4: Systems + data

Connect ERP, Anexo 24, Anexo 30/SCCCyG when applicable, warehouse movements, BOMs, scrap and fixed assets.

Phase 5: Finance + intercompany

Design inventory ownership, costing, intercompany pricing, customs value, AP/AR, FX and China HQ reporting.

Phase 6: Recurring governance

Review inventory/customs exceptions monthly, business-model changes quarterly, and prepare RAOCE/program maintenance in advance rather than waiting for an authority notice.

Which projects particularly benefit from an integrated IMMEX review before equipment or material ships?

Examples include:

a Chinese group operating a manufacturing entity in Mexico for the first time;
projects expecting significant temporary imports from China/Asia;
operations using submaquila, third-party warehouses or multiple factory locations;
a plant that exports but may also sell to Mexican customers;
a network that expects frequent virtual transfers with other IMMEX suppliers;
businesses with frequent SKU, BOM or engineering changes;
companies planning to use IVA/IEPS certification or guarantees;
U.S. customers that require USMCA origin support;
China HQ that wants one view of inventory, customs exposure, margin and intercompany balances; or
rapid ramp-ups where production volumes and supplier counts will expand quickly.

ASCG Pacific can start with the China → Mexico Expansion business model and connect IMMEX, Mexican tax/accounting, inventory control, intercompany and HQ reporting in one implementation plan. If the group also has a U.S. sales entity, Asia—U.S.—Mexico Cross-Border Coordination can align U.S. sales, Mexico manufacturing and China HQ around the same transaction facts.

Official references

This article reflects official rules and government information available as of August 2026 and is intended as general business, customs, tax and operating information. It is not legal, tax or customs advice for a specific transaction. IMMEX, temporary imports, submanufacturing, IVA/IEPS, USMCA and domestic-sales treatment should be confirmed against the company's actual goods, program, certifications, contracts and transaction facts.

This article provides general information only and is not tax, legal or accounting advice for any specific facts or circumstances.