Patent term: how to calculate the expiration date of an EP patent? - Obtaining an EP Patent - A crash course for the US applicant #7

04 April, 2024

Patent term: how to calculate the expiration date of an EP patent?

In most patent legislations, the duration of a patent is generally 20 years from the filing date. It has also been so in the US since June 7, 1995 but the term of a US patent depends on several other factors, which are the following ones:

If domestic priorities are claimed, the 20 years period starts from the earliest US filing date, excluding US provisional applications;
If a foreign priority under Paris convention is claimed, it is not taken into consideration in the calculation of the 20 years period;
The term can be extended by a Patent Term Adjustment (PTA) if delays attributable to the USPTO occurred during the examination proceedings;
The term can be shortened by a Terminal Disclaimer (TD) when a double-patenting issue occurred regarding other patents assigned to the same entity;
In the pharmaceutical field, the term can be extended by a Patent Term Extension (PTE) in order to compensate to time required to obtain the market authorization of a pharmaceutical product.

The USPTO provides a patent term calculator to help the public estimate the expiration date of a patent.

The EP standpoint

At first sight, the calculation of the expiration date of an EP patent looks simpler than the US one. Indeed, while the basic rule is the same (20 years from the filing date - article 63 EPC), there is no PTA and no TD.

If the patent is a division (there is no continuation in Europe), the 20 years period starts from the earliest EP filing date (there is no provisional application in Europe). When a priority under the Paris convention is claimed, it is not taken into consideration in the calculation of the 20 years period.

In the pharmaceutical field, the term of an EP patent can be extended by a special title called Supplemental Protection Certificate (SPC). However, SPCs are governed by national laws or the European Union law. There are no common proceedings between the EU member states¹. Moreover, of the non EU-countries which are member states of the European Patent Convention (EPC), only some provide an SPC (e.g. Switzerland but not Turkey) and each state has its own rule of calculation. Therefore, the eligibility for SPC protection and the duration of granted SPC have to be checked on a country-by-country basis.

Furthermore, the precise day on which an EP patent expires (i.e. the day on which it has no longer legal effect) varies depending on the national legislation of the member state. If the 20 year-period falls on day n, some states consider that the patent no longer have legal effect on day n (e.g. France), whereas other states consider that the patent no longer have legal effect on day n+1 (e.g. Greece).

As a US applicant, what should you do?

First, you should check if the application is a divisional application of an earlier application. If so, the 20 years period starts from the earliest EP filing date (excluding priorities under Paris Convention).

Second, if the invention is in the pharmaceutical field, you should check if SPCs were filed for this patent in each validated country. As already mentioned, this has to be done on a country-by-country basis.

Finally, if the determination of the precise day on which the patent expires matters for you (which is often the case in the pharmaceutical field), you should check how this day is determined (n or n+ 1?) on a country-by-country basis.

References