Contracts Executed Between Mexican Companies And Foreigners – The New Mexican Customs Requirements

Mexico's customs and foreign trade legal framework has evolved into a substance-based compliance model. Authorities now expect importers to demonstrate not only what was imported, but also why, under what legal relationship, and under what economic terms the transaction took place.

In this environment, contracts are no longer merely corporate or legal instruments. They have become core customs compliance documents, particularly for companies operating under the IMMEX (Industria Manufacturera, Maquiladora y de Servicios de Exportación).

The Electronic File and Recent Reform the Customs Legal Framework

Historically, many nearshoring and cross-border business models relied primarily on invoices, purchase orders, or internal intercompany policies to support import operations. Today, this approach is no longer sufficient.

Mexican importers are required to maintain a complete electronic file for each customs entry. This file includes the pedimento (Mexican customs clearance form) and its annexes, such as commercial invoices, proof of payment, customs valuation manifests, transportation documents, certificates of origin, NOM compliance documents, import permits, and technical information identifying the goods (e.g., weight, volume, serial numbers, parts, brand, model, and specifications).

Recent reforms to the Mexican Customs Law and related regulations have expanded these requirements. Importers must now also retain documentation that proves the resources used to carry out the foreign trade operation, in other words, evidence that the transaction actually occurred and has economic substance.

Some of the required documentation generally includes contracts that demonstrate:

• The purchase of goods or services related to imported merchandise
• Lease or ownership of facilities where goods are stored or production occurs
• Lease or ownership of machinery and equipment used in the operation
• Specialized services related to transportation, handling, storage, or production
• Royalties, licenses, or other intangible payments connected to the transaction

For foreign companies contracting with Mexican entities, this means the contract itself becomes part of the importer's customs file and must be consistent, coherent, and aligned with all other supporting documentation, this is a contract that reflects symmetry with the overall operation.

As a result, Mexican importers are expected to retain contracts executed not only with suppliers and customers, but also with service providers, landlords, logistics operators, and foreign related parties.

Key Contractual Considerations from a Customs Perspective

Mexican authorities increasingly assess whether contractual documentation reflects the economic reality of the operation. This review often focuses on ownership of goods, allocation of responsibilities, valuation mechanisms, origin, customs regime, use of assets, and payment flows.

A well-structured contract, or where applicable, a clear master contract, helps demonstrate the materialidad (substance) of the transaction, a concept that is now central to customs audits and IMMEX reviews.

Because contract negotiation and execution in Mexico can be formalistic and time-consuming, early planning is essential. As a starting point, contracts should clearly establish:

• The purpose and scope of the contract
• Effective date and term
• Place, time, and method of payment
• Identification of the importer of record
• Ownership of raw materials, machinery, equipment, and finished goods
• Valuation methodology, especially between related parties
• Allocation of customs, tariff, and compliance liabilities
• USMCA (T-MEC) origin and verification responsibilities
• Pricing structure and cost components
• Treatment of royalties, licenses, assists, or services as conditions of sale
• Whether payments outside the invoice affect customs value
• Applicable INCOTERM
• Insurance and place of delivery

In addition, contracts should address labor and subcontracting restrictions, tax and permanent establishment risks, governing law and jurisdiction, force majeure, language, notices, termination, assignment, amendments, and independence of the parties.

Practical Compliance Considerations

To strengthen compliance and audit readiness, importers should also:

• Align contracts with other documents in the electronic file
• Confirm whether certain contracts require notarization or registration to be enforceable against third parties
• Ensure the corporate purpose (objeto social) of each company is consistent with the contract
• Verify that the names and signatures of legal representatives match corporate records and official IDs
• Obtain and review supporting corporate documentation, including:
  • Notarial deeds evidencing legal existence
  • Mexican tax ID and proof of tax compliance
  • Notarized powers of attorney
  • Government authorizations or permits, where applicable

Companies should also be prepared for multiple rounds of review and negotiation, which may take weeks or even months before a final version is executed.

Can a Purchase Order Replace a Contract?

From a legal standpoint, a purchase order may qualify as a contract if it contains the essential elements of a binding contract, identification of the parties, goods or services, price, delivery terms, and acceptance, and is fully consistent with invoices, CFDI, and Customs records.

However, in practice, purchase orders may be insufficient on their own. Mexican authorities frequently expect a master contract (manufacturing, maquila, services, supply contract) that clearly defines ownership, responsibilities, and the overall operating model. In such cases, purchase orders should serve only as transaction-level supplements, not replacements.

From a conservative compliance perspective, maintaining a properly executed contract, or master contract, remains the recommended approach.

Conclusion

In the context of nearshoring operations and IMMEX programs, contracts are no longer optional formalities. They have become essential compliance tools that directly support inventory controls, temporary import obligations, authorized processes, and the legal existence of foreign trade operations.

While purchase orders may support individual transactions, they often lack the broader legal and operational context required by Mexican authorities. A well-structured contract, supported by consistent documentation, helps demonstrate substance, mitigate Customs and tax exposure, and withstand audits related to valuation, origin, VAT, and transfer pricing.

For foreign companies doing business in or with Mexico, investing in robust, aligned contractual frameworks is not just risk management, it is a strategic necessity for sustainable and compliant nearshoring operations.

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The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.