How long do patent rights last?

The duration of a granted patent is 20 years counted as from the filing date, i.e. the date on which the patent application was filed. Where priority from an earlier application is claimed, it is still the filing date and not the priority date which is relevant for the calculation of the 20 year term. Where the application is a divisional or a continuation application, it is the filing date of the parent application which is relevant for determining the start of the 20 year term. The maintenance of a granted patent requires the payment of maintenance fees in each country where the patent is in force.

In some circumstances it may be possible to get an extension of protection for a specific product covered by  a granted patent, which will extend the term of protection above 20 years. This is referred to as a “supplementary protection certificate” (see What is an “SPC” below).