Although the Mexican Law on Inventions and Trademarks enacted back in 1976 punished non-working of patents by considering them as lapsed if actual working was not effected in Mexico prior to 3 years as of grant or 4 years as of filing, whichever was longer, lapsing of patents in view of lack of working could be avoided by justifying such non-working with the filing of an "excuse affidavit" based on the Paris Convention, the effect of which was to merely subject the patent to the compulsory licensing system.
After January 19, 1987, the excuse affidavits were abolished for patents granted after said date and only actual working affidavits continued to be filed when necessary. If actual working affidavits were not filed, the patents were only subject to the compulsory licensing regime, but did not lapse.
In accordance with the present Law in force as of June 28, 1991 and its amendments of October 1st, 1994, working of patents is no longer compulsory. However, to prove actual working of a patent before the Mexican Patent Office (now Mexican Institute of Industrial Property) in order to fully avoid the possibility of grant of compulsory licenses, still remains as a convenient measure.
An important change included in this law is that the continuous importation of the patented products or of the products manufactured by the patented process may be regarded as constituting sufficient reason to prevent the grant of compulsory licenses. Said continuous importation is not expressly regarded by the law as actual working, although in practice it may be regarded as such, since it is absolutely sufficient to avoid the grant of a compulsory license.
In summary, the submission of excuse affidavits for justifying non-working of patents is no longer necessary and even useful. A patent will not lapse due to non-working but instead will fall in the compulsory licensing regime after the end of three years as of grant or four years as of the filing date, whichever term is longer.
A patent may lapse only if after the expiration of a term of two years as of the date of the grant of a first compulsory license said patent remains unexploited by a cause attributable to patentee. This is to be regarded as an extremely remote possibility because the grant of compulsory licenses in accordance with the law will be rejected if the patented product is being imported into Mexico, as stated above.
If no compulsory license is granted, which is the most probable situation, the patent will remain valid for all of its life term.
The content of this article is intended only to provide general guidelines related to this particular matter. For your specific circumstances, full specialist advise is recommended.
