The first half of 2026 has arguably brought about the most significant transformation in Mexican patent practice since the Industrial Property Law entered into force in 1991. Within the space of only four months, amendments to the law, the enactment of new regulations of the law, and administrative changes to the practice of the Mexican Institute of Industrial Property (IMPI) have substantially reshaped the way patent applications must be prepared, filed, and prosecuted in Mexico.
These developments go far beyond isolated procedural amendments. They represent a genuine shift in the Mexican patent system, requiring applicants to make strategic decisions much earlier in the life cycle of an invention, anticipate substantive examination issues at an early stage, and define the desired scope of protection even before substantive examination begins.
This article reviews the principal legislative and procedural changes, their practical implications for local and foreign applicants, and the adjustments that will be required to develop effective patent filing strategies in Mexico.
First reform: only two opportunities to convince the examiner
The first major change took effect on March 11 2026, when IMPI reduced the maximum number of substantive examination office actions that could be issued from four to two.
Following the applicant’s response to the second office action, the examination may only conclude with either the grant of the patent or a final refusal.
This reform is particularly significant because the Mexican patent system does not provide mechanisms comparable to the US request for continued examination or similar procedures allowing applicants to reopen substantive examination. Once a final refusal has been issued, the only available remedy is to initiate nullity proceedings before the Specialised Intellectual Property Chamber of the Federal Administrative Court, a considerably more complex, time-consuming, and costly process.
One positive development accompanying this reform is the possibility of holding virtual interviews with the examiner from the first office action onwards. Although the new rules remain silent as to the legal effect of any agreements reached during these meetings, they have the potential to become a valuable tool for clarifying technical issues and streamlining prosecution.
The real significance of the reform, however, lies not simply in reducing the number of office actions. Rather, it fundamentally shifts much of the technical and strategic work to the earliest stages of prosecution.
What does this mean for applicants?
Until now, it was relatively common practice to use the first office action to understand IMPI’s position and progressively adapt the claims as prosecution advanced in parallel applications filed and prosecuted by other patent offices.
That strategy is now becoming considerably less effective.
Applicants will need to determine their commercial objectives much earlier, prepare stronger claims from the outset, and anticipate potential examination objections before starting the examination.
Put simply, applicants will need to make strategic decisions much earlier than before.
Second reform: amendments to the Federal Law for the Protection of Industrial Property
The amendments to the Federal Law for the Protection of Industrial Property, published on April 3 2026, introduced several important changes affecting patent practice.
Among the most significant are the introduction of:
A provisional patent application system;
Mechanisms allowing for the restoration of priority rights;
New provisions aimed at preventing abandonment resulting from failures to comply with certain procedural requirements; and
Statutory deadlines within which to complete the substantive examination.
IMPI must complete the examination of a case within one year after starting the substantive evaluation of the subject matter. This reform once again requires applicants to define their protection strategy at a much earlier stage, leaving considerably less flexibility to postpone important prosecution decisions.
Third reform: the new regulations and divisional applications
The new implementing regulations significantly restrict the ability to file voluntary divisional applications.
Most notably, where an examiner raises a lack of unity objection, the subject matter removed from the parent application must be pursued in a divisional application. The term for filing any required divisional application is the same period established for responding to the unity objection. Failure to do so would result in the loss of the right to pursue protection for that subject matter.
Consequently, the common strategy of maintaining one or more pending divisional applications while commercial plans evolve or additional technical developments become available will become substantially more difficult under the new framework.
Once again, the message is clear: applicants will need to make strategic decisions much earlier.
Conclusions
The 2026 reforms represent far more than a legislative update. They constitute a fundamental transformation in the way patent protection must be approached in Mexico.
Success will depend less on an applicant’s ability to react during prosecution and more on the quality of the work carried out before filing and obtaining the appropriate legal and technical advice from local practitioners during prosecution. Applicants will need to define their commercial objectives at an early stage, prepare technically robust claim sets, and anticipate examination issues from the outset.
In other words, the new Mexican patent system rewards preparation and proactive prosecution considerably more than the ability to react during examination.
