Update to Mexican IP Rules: New Two-Office Action Limit for Substantive Examination

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Mexico’s New Two-Office Action Limit for Substantive Examination

A significant shift in Mexican patent practice is now in effect, fundamentally changing how inventors and practitioners must approach the in-depth examination stage. On March 11, 2026, the Mexican Institute of Industrial Property (IMPI) published an amendment to the rules governing response times and procedures for patent and utility model applications.

This update, signed by Director General Santiago Nieto Castillo, is part of a broader national policy focused on administrative simplification and regulatory improvement. For foreign agents and in-house counsel, this means the days of extended back-and-forth negotiations with Mexican examiners are narrowing.

The New Rule: Two Strikes and You’re Out

The published amendment concerns Article 11 of the Agreement for Establishing Response Times for Various Procedures Before the IMPI. Effective for applications filed on or after March 12, 2026, IMPI has officially capped the number of requirements (office actions) that can be issued during the substantive or “in-depth” examination of a patent or utility model.

Under the new framework, the Institute may issue a maximum of two office actions to allow applicants to clarify, amend, or correct omissions in their applications. Previously, practitioners often navigated up to four rounds of substantive office actions. By cutting this limit in half, IMPI aims to accelerate the path to either a grant or a final rejection. The formalities examination stage still allows for two office actions, typically issued prior to publication of the application.

Transitional Provisions

It is important to note the transitional rules included with the publication:

  • New Applications: Those filed on or after March 12, 2026, are subject to the strict two-office action limit.
  • Pending Applications: Applications filed before this date will be resolved according to the rules in effect at the time of their filing, meaning they may still receive up to four office actions during the substantive examination phase.

Formalizing the Virtual Interview

To balance the reduced number of written exchanges, the amendment formalizes the use of “reuniones telemáticas” (telematic or virtual meetings). This move suggests IMPI is leaning into a more collaborative, “face-to-face” resolution strategy to resolve technical impediments.

  1. Applicant-Requested Interviews: During the in-depth examination, the applicant may request a virtual meeting related to the patent or utility model process.
  2. IMPI-Proposed Interviews: Upon issuing the first substantive office action, the Institute may now proactively propose a virtual meeting to analyze protection hurdles identified in the state of the art.

While virtual interviews were already occurring in practice, their inclusion in the official agreement signals a shift toward using them as a primary tool to overcome objections early. However, practitioners should be aware that the language is somewhat ambiguous regarding whether an applicant is limited to only one such interview per case.

Strategic Implications for Foreign Counsel

Because Mexican law does not currently provide an equivalent to a “Request for Continued Examination” (RCE), the stakes for each response have doubled. If an application does not overcome all objections by the second office action, it will likely face a final rejection. Challenging such a rejection typically requires expensive and time-consuming administrative reviews or court actions.

To navigate this new landscape, consider the following strategies:

  • Front-Load the Prosecution: Treat the first office action response as the most critical filing. Ensure all technical arguments and claim amendments are robust enough to potentially wrap up the case in one go.
  • Leverage PPH and Foreign Work Products: IMPI remains open to considering results from foreign offices. Utilizing Patent Prosecution Highway (PPH) programs can often align the Mexican examination with allowed claims from other jurisdictions, reducing the likelihood of multiple office actions.
  • Embrace the Interview: Given the two-action limit, a virtual meeting with the examiner after the first office action is no longer just an option; it is a vital tool to ensure the second office action is the final step toward allowance.

Looking Ahead

These changes are expected to significantly shorten the pendency of patent applications in Mexico. While the speed is a welcome change for many industries, it places a higher premium on precision and early-stage strategy. By adapting to these rules now, international applicants can ensure their intellectual property rights in Mexico remain secure without the need for protracted litigation. If you want to chat about how to pivot your strategy for these new IMPI rules, feel free to reach out to us at WJB through our contact page.