If an authority grants two patents for the same invention to the same applicant, that is double patenting. In most European states the law requires that one of the patents must cease.

Since it started, the European Patent Office (EPO) official view has been that it should not allow double patenting. The Guidelines for Examination explicitly state this. However, the governing European Patent Convention (EPC) makes no mention of double patenting.

A recent Technical Board of Appeal (TBA) decision, T 307/03, tried to find basis for the prohibition of double patenting in the EPC provision governing ownership of the invention.

The recent TBA decision T1423/07 rejects T 307/03 and confirms that the EPC gives no legal basis for any EPO prohibition of double patenting. The TBA decided there is nothing in the EPC explicitly prohibiting an applicant obtaining two patents for an invention, provided the applicant has a legitimate interest in doing so.


This decision makes it more difficult for the EPO to refuse, on the grounds of double patenting, a divisional application to subject matter similar to that of the parent application.

However, the decision left open the possibility of refusing such an application if the applicant does not have ‘a legitimate interest’. We await the reaction of the EPO examiners with interest.

Please do not hesitate to contact us if you have any questions or if you would like further information.

Today’s post is by Guest Barista Matt Barton, a UK Chartered Patent Attorney and European Patent Attorney at Forresters in London.

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  1. […] This post was mentioned on Twitter by IPwars (wrothnie) and Claude Fournier, Patent Agent 007. Patent Agent 007 said: "The recent TBA decision T1423/07 … there is nothing in the EPC explicitly prohibiting [double patenting]" http://is.gd/cAK4W […]