PCT is the Patent Co-operation Treaty. It is administered by the World Intellectual Property Organisation (WIPO). The PCT system facilitates filing of patent applications under a single entity and provides for a simplified process for the search and examination of such applications. A resident or national of a PCT member state files a PCT application. This helps to get the effect of patent filings in any or all of the PCT countries and the applicant will get the same priority date in all these countries subject to certain conditions. The applicant is able to defer the bulk of filing costs in each of these countries due on filing.
The PCT applications should be filed in an approved receiving office (as per the relevant rules in your country) or at the WIPO International Bureau in Geneva. There are two phases in PCT – the international phase and a national phase.
The National Phase commences after applications are filed in each country selected separately. This should be accomplished before the expiry of the relevant timeframe. Patent rights will be lost if the applicant fails to apply in time.