Patent offices in most countries in the world (currently totalling 148 countries) signed a PCT (Patent Cooperation Treaty) in order to unify the processing of applications, search reports and examinations, by virtue of which an invention for which protection is sought in several of the member countries may be processed by means of one single international application under the PCT convention, rather than having to process the application separately in each one of said countries. This application will then be analysed and examined by one of the signing offices, which will determine whether or not it meets the requirements to be fulfilled in order for patent protection to be granted.
PCT applicants may opt for the search to be carried out at their national office, if this is possible under the treaty, or failing that, at another office in a country that has signed the agreement. For example, it is possible to request that the search be carried out at the EPO (European Patent Office) or OEPM (The Spanish Patent and Trademark Office).
As a patent is being processed under the PCT, a background search is carried out and a written opinion is received from the examiner. It is also possible to request a preliminary examination. It can take up to thirty months as of the date the application was filed for a PCT application to be fully processed. During this time, the patent application would be listed as pending in all countries that signed the PCT treaty. Before the thirty months come to an end, the client must choose which countries they wish the procedure to continue in, be it at national or regional level (for example the EPO), choosing countries that have signed the PCT treaty, until protection is awarded definitively.
You can find out which countries signed the PCT agreement by looking at the figure attached or by visiting the PCT website