Doing Business Under Mexico’s New Competition Regime

In collaboration with Paola Gonzalez, Associate. 

Mexico's competition regime is undergoing its most significant transformation in more than a decade. In July 2025, the autonomous Mexican Competition Authority was replaced by the National Antitrust Commission (CNA), a decentralized body attached to the Ministry of Economy. The Competition Law was substantially amended: monetary thresholds for mandatory merger filings were lowered; fines and daily coercive measures were increased; investigative powers were expanded, including in sectors previously overseen by the telecommunications regulator; procedural deadlines were shortened; stricter conditions were introduced for leniency benefits; and certified compliance programs became a potential mitigating factor. In parallel, the judicial reform of September 2025 redesigned the federal judiciary, including the specialized competition courts.

This is a critical moment. Not because institutional change is comfortable — it rarely is — but because moments of redesign are precisely when legal and business communities must be most attentive, critical, and prepared.

Why Does Competition Law Exist? 

Competition law protects the process through which independent economic agents interact freely in the market. That process supports consumer welfare, productivity, and Mexico's integration into North America. The development of antitrust and competition law in Mexico was driven by NAFTA, which required a functioning competition regime in each of the three jurisdictions. USMCA continues to rely on that assumption and is about to be tested again in the upcoming review negotiations. A predictable, legally rigorous competition authority remains one of the most important conditions for Mexico's growth.

For executives operating in — or into — Mexico, the practical question is no longer whether the framework has changed. It is what to do about it. The following are eight considerations that should be on the agenda of any board, general counsel, or country manager doing business in Mexico today.

1. Watch your merger thresholds — and your calendar. Transactions meeting monetary or asset-value thresholds must be notified to the CNA and cleared before closing. Because the reform lowered thresholds, more deals are now captured, and filing fees increase across statutory ranges depending on transaction value.

Once the file is complete, review can be fast: the CNA reported an average review period of 17.3 business days in the second quarter of 2026. That creates an opportunity for well-prepared filings, but it also makes early planning essential. Failure to notify, or closing before clearance, is being actively enforced, with MX$39.8 million (US$2.3 million) in fines imposed in that same quarter alone.

2. Every day is gold when responding to information requirements. Article 73 of the Competition Law sets a uniform ten-business-day deadline to respond to requests for information, extendable only once for the same term. The Supreme Court upheld that framework (RA 135/2026), while leaving room to challenge arbitrary requests in specific cases.

The operational lesson is simple: internal protocols must exist before a request arrives. Companies should know who receives notifications, assembles the working group, owns each substantive response, documents impossibility, and signs the filing. That preparation matters in merger reviews, investigations, market studies, and barrier-to-competition inquiries alike.

3. Preserve your records — for at least 10 years. The Commercial Code requires companies to preserve books, records, correspondence, and documents for at least 10 years [Article 46]. Although this does not necessarily limit the CNA’s ability to request older information, it defines what companies can realistically produce and helps assess whether a request is reasonable.

The 10-year window should therefore be actively managed through clear retention policies, structured storage, and reliable retrieval. In an investigation, failing to locate records that should have been preserved is materially different from having disposed of them lawfully under a documented retention policy.

4. Expect requests for information held by your parent company. Mexican subsidiaries of international groups should expect requests for information held by foreign parents, particularly when it concerns the Mexican market. Specialized courts have held [RA 179/2025; RA 136/2026] that a subsidiary may be required to obtain that information, and that simply stating that the parent holds it will not suffice. The subsidiary should document that it requested the information and, if applicable, that access was denied.

For multinational groups, intragroup information architecture is now a compliance issue: where is Mexican-market information stored, who can request it, and how quickly can the group provide or formally refuse it?

5. Compliance programs are more attractive than they used to be. The CNA’s ability to certify compliance programs, coupled with the possibility that certification may reduce penalties, makes these programs significantly more valuable. While detailed guidance has not yet been issued, standards applied by authorities such as the US DOJ, Brazil’s CADE, and Colombia’s SIC offer a useful indication of the elements that robust and credible programs should include.

Effective programs cannot exist only on paper. It should be backed by leadership, led by a compliance function with real authority, informed by risk assessments that reflect the company’s actual market dynamics and contacts with competitors, and supported by reliable reporting mechanisms, periodic audits, and concrete corrective measures. They also improve a company’s ability to detect issues early and access leniency if needed. For companies that already have a compliance program, this is the moment to test it — before the CNA does.

6. Rebuild the case you make in court. The specialized competition courts have been reconfigured under the judicial reform. For practitioners, this is not merely procedural; it changes how cases should be argued. The CNA’s 2026–2030 Institutional Program and Annual Work Program emphasize welfare, prices, market access, and consumer benefit.

Technical arguments — relevant market, market power, counterfactuals, efficiencies — remain necessary, but should be connected to concrete effects on consumers, competitive access, and Mexican productivity. The judicial audience has changed, and persuasive framing must change with it.

7. The class-action risk is real — and building. Class actions in competition matters are no longer theoretical. They are expressly included in the CNA’s Institutional Program 2026–2030, and several recent collaboration agreements signed by the CNA include information-exchange language that could support them.

The procedural gate has also opened. The Supreme Court held that COFECE resolutions finding liability for monopolistic practices or unlawful concentrations are enforceable by operation of law, even if amparo proceedings remain pending (RA 3/2025).

An infringement finding may therefore trigger not only fines and reputational harm, but also private damages exposure. Provisioning, insurance, disclosures, and dispute-resolution playbooks should be reviewed accordingly.

8. Understand what has changed in the immunity program. The reform tightened the leniency regime. Full immunity is now concentrated in the first cartel participant that satisfies the strictest requirements; later applicants may receive reductions, but the gap with the first applicant is now more significant.

The practical rule is clear: in cartel exposure, speed is the strategy. Companies with live compliance systems are better positioned to detect first, decide first, and file first. Those without them often arrive second — or too late for the information they can provide to remain valuable enough for the authority to grant a meaningful benefit — thereby increasing the risk of criminal consequences.

The Road Ahead

Mexico’s new competition regime asks more of the private sector: lower thresholds, faster reviews, shorter response windows, broader information demands, heavier sanctions, a consumer-welfare-oriented judicial audience, rising class-action exposure, and a leniency regime that rewards the fastest applicant.

Each change is manageable if anticipated. The best-prepared companies will be those that treat competition compliance as a live operational discipline, not as a document filed away.