When it comes to infringement actions, two dates are of particular importance: date of publication and date of grant. Where a competitor files an application in respect of subject matter that you are, or may be, already using, and there is a risk that you will be infringing the patent if granted, you may seek to defeat, or at least delay, the application. In either case, you will need to pay close attention to these two dates.

Patent infringement lawsuits can only be filed after grant of the patent in question. However, pursuant to Article 35bis of the Patent Act, damages for infringement may, in certain circumstances, be calculated from the date the application was published in the Patent Gazette. Article 35bis provides that a patentee will be entitled to damages in respect of an infringing act carried out after the date of publication of the application, provided the infringer was, at the time, aware of the application.

The current procedural framework that regulates patent oppositions allows pre-grant opposition proceedings. Any third party is allowed to file an opposition within a period of 90 days after publication of the application. Several grounds, either alone or combined, can be used as the basis of an opposition including lack of novelty or inventive step, non-patentable subject matter, or the applicant's entitlement to file the application and be granted a patent in Thailand. Often, the 90 day period allowed for filing an opposition, will already have expired before a decision to oppose has been taken. In that case, although it is not possible to file a formal opposition, it is possible to notify the Examiner, informally, of any relevant prior art or any Office Actions that have been taken in relation to the priority or corresponding applications. Although the Examiner is not obliged to consider such notifications, in practice, most Examiners will do so.

Normally it takes years for oppositions to be considered; meanwhile, examination of the application and grant of the patent are delayed.

Apart from delaying grant, successful opposition proceedings will, of course, ensure that the application does not proceed to grant, thus removing the risk of future infringement.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.