Claiming Convention Priority

ly updated October, 1996

A national (citizen or company resident in one of the Union member countries) who applies for a patent in one Union member country, can wait up to a year to file applications in other member countries and can rely on the first application date (the priority date) to effectively backdate the later filed applications to the first filing date.

For example, if you are a Canadian, and you filed your first application in Canada on December 1, 1995, then you can file applications in other convention countries on or before December 1, 1996, claim the benefit of convention priority, and your application is entitled to be treated as if it had been filed in those other countries on the date you filed the application in Canada. In our first-to-file system, the entitlement to obtain a patent is based upon priority dates, where they exist ( Patent Act, s. 28(1) ).

The convention priority date is taken into account with respect to prior public disclosure by third parties ( Patent Act, s. 28(1)(c) ). In other words, you must get a patent application on file somewhere, before other inventors make the invention public.

The convention priority date is not taken into account with respect to prior public disclosure by the inventor or his disclosees ( Patent Act, s. 27(1)(c) ). In other words, you must get your patent application on file in Canada, within one year from making your invention available to the public.

You must claim the benefit of convention priority within a certain time period ( Patent Act, s. 28.4(2) ): within four months of filing your application ( Patent Rules, s. 88(1)(b) ) for applications filed on or after October 1, 1996 [or six months for pre-October 1, 1996 applications]. The Patent Office may require an Applicant to file a certified copy of the foreign application upon which convention priority is claimed.