With some European states which are not a party to the EPC and thus not "included" in the designation "EP", the EPO has concluded so-called "extension agreements". Pursuant to such agreements and the relevant national law, it is possible for applicants to extend European patent applications and patents to extension states, where the extended patents will confer essentially the same protection as patents granted by the EPO for the current 38 member states of the European Patent Organisation. Valid extension requires firstly that the applicant submits a request for extension and pays the extension fee(s) in due time, i.e. within 31 months from the date of filing (or the earliest priority date) or six months from the date of publication of the international search report, whichever is the later. A further requirement is that, on the international filing date, the extension agreement has to be in force and the extension state must both be a PCT contracting state and be designated for a national patent in the international application.