After filing your PCT application, an International Searching Authority (ISA) will perform a search of relevant patent documents and references. Additionally, the ISA will issue a preliminary and non-binding review of the claims, analyzing them to see if they satisfy novelty, inventive step and industrial applicability standards. The International Search Report and Written Opinion are sent out approximately 4 months after the PCT filing date (16 months after the priority date).
If desired, the applicant can request further international searches from one or more ISAs which have indicated their availability to perform supplemental searches. There are two fees for requesting the supplemental search – a search fee set by the ISA performing the additional search and a CHF 200 search handling fee to the International Bureau. Usually, this request is submitted after the applicant has received the International Search Report, but no later than 19 months after the priority date. The Supplemental International Search Report usually issues 28 months after the priority date, right at the time when the applicant is deciding where the application will enter the national stage.
The benefit of requesting a supplemental international search is pretty obvious. Having additional sets of eyes searching the prior art base means reducing the chances of any unanticipated prior art popping up during examination. Since foreign filings can be quite expensive, having a complete picture of the prior art and one’s likelihood to receive a patent can help an applicant formulate their strategy before entering the national stage.