Due Diligence Guide for M&A Transactions in Mexico

Due diligence is the investigation and verification process conducted by a potential buyer before completing a mergers and acquisitions (M&A) transaction. In Mexico, where the regulatory framework presents significant particularities and informality can generate hidden risks, rigorous due diligence is not optional: it is the difference between a successful acquisition and one that generates multimillion-dollar contingencies.

Types of due diligence

Legal (corporate) due diligence

Corporate legal due diligence examines the corporate status of the target company. It includes a review of the articles of incorporation and their amendments, verification of the company's legal existence in the Registro Publico de Comercio, analysis of the shareholding structure and chain of title, review of existing powers of attorney and their scope, minutes of shareholder meetings and board sessions, and verification of compliance with corporate obligations (SAT filings, registrations, annual reports).

In the Mexican context, it is particularly important to verify that bylaw amendments have been duly notarized before a public notary and registered with the Registro Publico de Comercio. Failure to register can create enforceability issues against third parties under the Ley General de Sociedades Mercantiles.

Labor due diligence

Given the protectionist nature of Mexican labor law, the labor review is frequently where the most significant contingencies are discovered. The analysis must cover individual employment contracts (verifying compliance with the requirements of Article 25 of the Ley Federal del Trabajo), collective bargaining agreements and union relationships, status before the IMSS and INFONAVIT (including potential differences in the integration of the contribution base salary), compliance with employee profit sharing (PTU), STPS inspection records, and compliance with NOM-035 and NOM-037.

The 2021 outsourcing reform added an additional layer of complexity: it is essential to verify that all specialized service contracts have a valid REPSE registration and that providers are current on their tax and social security obligations, as the contracting party may be jointly and severally liable.

Tax due diligence

The tax review must cover at least the last five fiscal years (the general statute of limitations period under the Codigo Fiscal de la Federacion). Key points include the tax status before the SAT, filed tax audit reports, pending tax credits or disputes, compliance opinions, transfer pricing studies (for related-party transactions), the correct treatment of VAT and ISR, and the existence of applied tax benefits or incentives.

Environmental due diligence

For industrial and manufacturing companies, environmental due diligence is critical. Mexico has an extensive environmental regulatory framework administered by SEMARNAT and state environmental authorities. The review must include environmental and operating licenses, environmental impact assessments, hazardous waste generation registrations, annual operating certificates, and the potential existence of environmental liabilities (soil contamination, groundwater) that may represent extraordinary remediation costs.

Regulatory and competition due diligence

Depending on the sector and the size of the transaction, it may be necessary to obtain authorization from the Comision Federal de Competencia Economica (COFECE). The Ley Federal de Competencia Economica establishes mandatory notification thresholds based on the transaction value, the parties' revenues, or the value of the assets involved. Closing a concentration without the required authorization can result in fines of up to 8% of the offender's revenues and the nullification of the transaction.

Common red flags in the Mexican market

• Share ownership irregularities: Blank-endorsed shares, outdated shareholder registries, or shares transferred without the required legal formalities.
• Hidden labor contingencies: Under-registration of employees before the IMSS, incorrect integration of the contribution base salary, unreported labor lawsuits, or informal agreements with workers.
• Tax exposure: Use of aggressive tax planning schemes, transactions with companies that issue invoices for simulated operations (EFOS), or inconsistencies between tax returns and accounting records.
• Real estate issues: Properties without properly registered deeds, undisclosed liens, irregularities in land use or construction permits.
• Regulatory non-compliance: Operating without the required sector-specific licenses or permits, or with expired permits or permits in the process of being revoked.
• Undisclosed litigation: Civil, commercial, or administrative lawsuits that have not been reported to the buyer during negotiations.

Typical timeline and key documents

A standard due diligence process in Mexico typically takes between 4 and 8 weeks, depending on the complexity of the target company. Information is typically shared through a virtual data room organized by subject matter. Key documents that the buyer should request include:

• Articles of incorporation and all notarized amendments.
• Share registry book and share certificates.
• Annual ISR and VAT returns for the last five fiscal years.
• Material contracts in force (clients, suppliers, leases, financing).
• Employee files and evidence of REPSE compliance.
• Valid permits, licenses, and regulatory authorizations.
• Complete list of pending litigation and administrative proceedings.

Considerations for cross-border transactions

When the buyer is a foreign company, the due diligence must address additional aspects: compliance with the Ley de Inversion Extranjera (sector restrictions), the existence of double taxation treaties between the jurisdictions involved, reporting obligations before the CNIE, implications of the Ley Federal para la Prevencion e Identificacion de Operaciones con Recursos de Procedencia Ilicita (Anti-Money Laundering Law), and considerations regarding foreign exchange controls and dividend repatriation.

It is also essential to consider anti-corruption regulations applicable in the buyer's jurisdiction, such as the Foreign Corrupt Practices Act (FCPA) of the United States or the UK Bribery Act, which may have significant extraterritorial implications.