Here we explain how the priority year works.

Anyone who files a patent application in a country that is a signatory of the Paris Convention or the WTO has the right to, within 12 months (the priority year), file an identical application in another country and claim priority from the first application. The first application is then the basis of the right to priority. The right to priority gives you many advantages.

In terms of novelty, priority means that your later application is regarded as having been filed at the same time as the first application. The date of filing of the first application is known as the priority date. An early priority date can give you precedence over others who try to patent the same or a similar invention.

If you want to claim priority based on a previous application, you must do so within 16 months of the priority date, or within four months of the filing date of your new application, whichever is later.

If you file your foreign applications within the priority year:

  • You can postpone spending time and money on foreign patenting until you have received a report on the patentability of the invention.
  • You can make your invention public as soon as you have filed your first patent application, without destroying its novelty value abroad.
  • You can keep the novelty value even if someone else has applied to patent the same or a similar invention in the meantime (between your priority date and your filing date abroad).

If you wait until after the end of the priority year to apply for a patent in another country, you lose the chance to claim priority based on your first application.


You have filed a patent application in Sweden for a kind of packaging. Now you want to patent the same packaging in Germany, England, France, Japan and the USA. Within one year, you can file national applications in these countries and claim priority based on your Swedish application.

This means, in terms of novelty, that your application is regarded as having been filed at the same time in all these countries – on the same date as you filed your application in Sweden.

You can also take advantage of the priority year if you choose to file a PCT application or a European patent application.

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Digital Access Service (DAS)