As you may know, the new Regulations of the Federal Law for the Protection of Industrial Property (“Regulations of the Federal Law”) were published on April 28, 2026, and will come into force on July 22, 2026.
New restrictions for the filing of divisional applications in Mexico will come into force.
To understand the new restrictions, we need first to explain the current practice under the Federal Law of Protection of Industrial Property (“Federal Law”) that came into force in 2020. Mostly, the “Federal Law” distinguishes voluntary divisional applications from divisional applications requested by the MX Patent Office. Voluntary divisional applications are applications filed according to the desire of the applicant. On the other hand, divisional applications requested by the MX Patent Office are handled through a unity objection at the in-depth examination.
Additionally, the Federal Law is restrictive regarding the filing of new divisional applications; for example, voluntary cascade divisional applications are not accepted. That is, Cascade Divisional Applications are divisional applications that derive from another divisional application.
Furthermore, it is a must that the applicant pursues Invention/design 1 as a response to the Office Action. We are not able to pursue in the Parent case another invention/design. For example, if the Office Action divided your invention into three parts and you want to pursue Invention 2 only, it is a must that we file it in a divisional application.
Moreover, when there is a lack of unity, the Applicants are required to file all possible divisional applications separately (I.E., a divisional application per each invention/design), instead of filing a single divisional application for the remaining claims and waiting for a new unity rejection in the in-depth exam of the divisional. This increased the prosecution costs to the applicants and does not allow the applicant to try to gain some time by filing in different time lapses the requested divisional applications.
Furthermore, when the Examiners raise unity rejections, they base their objection under provisions of Articles 93, 100, 102, 113 and 117 of the “Federal Law”, which reads as follows:
Article 100. In the case of divisional applications filed voluntarily or at the request of the Institute, the applicant must comply with the following requirements:
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- Claim an invention different from that claimed in the initial application and, where applicable, in other divisional applications, without containing additional material or material that broadens the scope of that initially presented.
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When, as a result of the division, an invention or group of inventions has been discontinued, these may not be claimed again in the initial application or in the application that gave rise to the division, as the case may be; and
III. File the divisional application within the time limit referred to in Article 111 of this Law or, when the division is voluntary, in accordance with Article 102.
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Article 102. The applicant may voluntarily divide an initial application that is still pending, complying with the provisions of Article 100 of this Law, maintaining the same filing date as the initial application for each divisional application and, where applicable, the claimed priority date.
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Article 111.- When, during the substantive examination, any impediment to the granting of the requested patent is detected, the Institute may require the applicant to state, within a period of two months, what is convenient for him or her, present information or documentation and, if appropriate, modify what he or she deems appropriate, indicating the modifications made.
Article 117.- The interested party will have an additional period of two months to comply with the requirements referred to in articles 103, 106, 110 and 111 of this Law, without the need for a request and verifying the payment of the fee corresponding to the month in which compliance is given.
But what are the new restrictions?
In light of the above articles, even though the “Federal Law” established a period of two-four months f or the filing of the requested divisional applications, it was NOT forbidden to file the divisional applications voluntarily if the Parent application had the status of “pending”. This legal window was exploited by the applicants.
However, the new Article 49 of the “Regulations of the Federal Law” reads:
If the Institute requires the division of an application, pursuant to the second paragraph of Article 113 of the Law and the provisions of these Regulations, and the applicant fails to submit the required applications within the period referred to in Article 111 of the Law, the subject matter of the division shall be deemed not to have been claimed.
The applicant may not subsequently submit, voluntarily, further divisional applications regarding the subject matter mentioned in the preceding paragraph.
Hence, according to “Regulations of the Federal Law”, the deadline for the filing of a divisional application, requested through an Office Action, is the same as that for responding to the said Office Action. Henceforth, if we do not file the divisional within that time-lapse, the matter claimed in the remaining inventions will be considered abandoned. It is explicitly forbidden to file a voluntary divisional application for the matter considered in the groups divided by the Examiner.
Henceforth, under the provisions of said Article 45, the possibility to file voluntary divisional applications for matter that was not filed in a divisional application at the fourth month term of the unity rejection will not be accepted.
Here are some questions and answers to better understand the above:
- Have you received any additional guidance or informal indications from the MX Patent Office regarding how Article 49 will be interpreted or enforced in practice?
No, the MX Patent Office has not provided any indications of how Article 49 will be enforced in practice.
- Although the Regulations formally apply to applications filed on or after July 22, 2026, do you believe the MX Patent Office may apply these provisions retroactively or take adverse positions with respect to currently pending applications?
The Third Transitory of the Regulations states that matters in process when the Regulations enter into force “will be governed and processed until their conclusion in accordance with the provisions in force at the time of their submission.” This is a strong non-retroactivity clause for pending matters as of July 22, 2026, though it allows access to certain ADR mechanisms. Accordingly, I do not expect the MX Patent Office to apply Regulation Article 49 retroactively to steps taken before July 22, 2026; pending files should continue under the prior regime through conclusion.
3) If a lack-of-unity objection is already on file and no divisional has been filed, should desired divisional applications be filed before July 22, 2026?
As a risk-managed approach, yes—where feasible. Although the Third Transitory protects the pending application as of entry into force, Regulation Article 49 establishes a stringent consequence for not filing required divisional applications within the Article 111 “Federal Law” term going forward. Filing desired divisional applications before July 22, 2026 reduces any risk of interpretive disputes.
4) Would failure to file within the MX Patent Office’s term completely bar later voluntary or cascading divisional applications for the non-elected matter?
Under Regulation Article 49, if the MX Patent Office requires division under “FEDERAL LAW” Article 113 and the applicant does not present the divisional(s) within the Article 111 term, “the subject matter of the division will be considered unclaimed” and the applicant “may not subsequently, voluntarily, present divisional applications” on that subject matter. In parallel, “Federal Law” Article 100 already restricts “division of a divisional” unless the MX Patent Office considers it appropriate or requires it (linkage with art. 113). Together, this means: failure to file within the set term bars later voluntary divisional applications on the non-elected matter and sharply limits cascading divisional applications.
5) Do you expect transitional rules, official guidelines, or practice notices?
Possibly. The Regulations expressly empower the Director General to issue “Agreements” for procedures and criteria (Regulation art. 5). It is reasonable to anticipate practice notices in the Official Gazette of the Federation addressing transitional handling at or after entry into force.
6) Commentary or concern about constitutional/due-process/retroactivity challenges?
When the Federal Law changed in 2020, unfortunately, the MX Patent Office did not take into account the legal principle of non-retroactivity of the law established in the Mexican Constitution; however, the Third Transitory’s “no retroactivity for matters in process” language reduces that risk.
7) Will cascading divisionals still be permitted when the original divisional was timely filed in response to a unity objection?
Cascade divisional applications are only permitted by means of a unity rejection at the in-depth exam.
8) Immediate actions for portfolios before July 22, 2026
- Audit all pending files with unity objections and identify non-elected inventions with commercial value.
- Where appropriate, file any protective divisional applications before July 22, 2026 to avoid future Article 49 disputes.
9) Practice recommendations for PCT national phases entering Mexico
- Draft and enter with claim sets structured around a single general inventive concept, if possible.
- Anticipate unity objections; pre-plan divisional paths consistent with Article 100 (no added matter; distinct inventions).
- Plan to file all desired voluntary divisional applications before the application loses the status of pending.
10) Do you anticipate increased precautionary divisional applications before July 22, 2026?
Yes. Given the explicit bar in Regulation Article 49 and the desire to preserve non-elected subject matter, a surge of precautionary divisional filings before July 22, 2026 is likely as a risk-mitigation measure. This is a practice forecast, not an official statistic.
11) If applicants later see value in non-elected matter but did not timely file a divisional, is any mechanism left?
Options will be extremely limited. Regulation Article 49 deems the subject matter “not claimed” and bars later voluntary divisional applications on that matter. Possible—but contingent—avenues are:
- Challenge the unity requirement (within the original term) if still procedurally open; once expired, the Regulation’s bar applies.
- File a new application only if the content remains novel/non-obvious over the art, noting that publication of the original file likely destroys novelty.
- If the Parent case has the status of pending, file a divisional application with all the claim-sets that the applicant wants to prosecute and wait for the in-depth exam.
12) Fees, timing, translation, or procedural considerations when filing multiple divisionals with a unity response
- Each divisional is a separate application with its own fees and formal parts; each must claim a different invention and cannot add matter or broaden beyond the initial disclosure.
- The applicant should be prepared to incur the payment of fees for the filing of multiple divisional applications in a short period of time.
- The timing is the same as that for responding to the Office Action.
13) Will these changes also impact foreign design applications or Hague designations in Mexico?
For Industrial Designs and Hague Designs, there will be no changes in the prosecution. Because in both legal figures, the deadline for filing any divisional application is the same as that for responding to the Office Action or Refusal.
In legal practice, even though the Federal Law does not contemplate it, the only possibility for filing a divisional application is with the originally filed drawings in the application; we cannot add new figures for new divisional applications to try to get a different scope of protection. Henceforth, all divisional applications filed in Industrial Designs and Hague Designs are by means of a unity rejection.
Please bear in mind that, according to the legal practice of the MX Patent Office after the publication of the Federal Law in 2020, divisional applications filed after the two-month term of a unity rejection are NOT accepted.
By: Fabián Ocampofocampo@uhthoff.com.mx
