While the current Mexican IP law is silent about the conditions and deadlines to file and accept divisional patent applications, the practice regarding those applications in Mexico is as follows:
Voluntary divisional applications can be filed at any stage during prosecution prior to the payment of the grant fee or the issuance of the Final Rejection for the parent application.
Sequences of divisional applications, also known as cascade divisional applications, are accepted without any restriction regarding the number of divisional applications that can be filed.
Divisional applications resulting from a requirement of the Mexican Patent and Trademark Office (MXPTO) can be filed when responding to the office action objecting the lack of unity of invention. Nevertheless, they are also accepted before the payment of the grant fee or the issuance of the Final Rejection for the parent application.
Even though the new Mexican Federal Law for the Protection of Intellectual Property provides some clarity regarding the current practice, it also provides some restrictions for divisional applications.
The new IP Law mainly includes the following provisions regarding divisional applications:
Voluntary divisional applications could be filed up to before the issuance of the decision rejecting, abandoning, or withdrawing the application. If the parent application is allowed, voluntary divisional applications can still be filed before paying the grant fees. Multiple voluntary divisional applications can be filed provided that they are filed at the same time.
The new IP Law stipulates that a divisional application cannot consist of divisions from other divisional applications, unless the MXPTO decides that the further division will proceed, or in cases where the MXPTO requests further division due to the lack of unity of invention. The effect of this appears to be that voluntary cascade divisional applications will be no longer allowed unless those divisions are required by the MXPTO.
Divisional applications resulting from a requirement of the MXPTO must be filed along with the response to the office action objecting to the lack of unity of invention.
Likewise, the new IP Law provides that the invention pursued in the divisional application must be different to that claimed in the parent case and other divisional applications. The new IP Law also includes restrictions about the subject matter that can be pursued as a result of the division of an application, since it provides that when an application is divided, either voluntarily or due to a requirement of the MXPTO, inventions or groups of inventions which are no longer claimed cannot be pursued again in the initial application or in the application which originated the division.
Although the new IP Law clarifies some conditions to file and accept divisional applications, it also includes limitations which were not present in the current Law. The final regulations pertaining to the new IP Law are pending so that the interpretation of its limitations and criteria for the MXPTO will need to be clarified once the new IP Law enters into force.
According to the transitional articles of the new IP Law, prosecution of applications pending when the new law enters into force will continue pursuant to the former IP Law.