In a Federal Register notice published earlier this month (80 Fed. Reg. 60367), the U.S. Patent and Trademark Office announced a change in practice for the correction of errors in foreign priority claims.  Under the change in practice, applicants wishing to correct errors in a foreign priority claim after the time periods set forth in 37 C.F.R. § 1.55 will have to file a petition under 37 C.F.R. § 1.55(e) and pay the petition fee under 37 C.F.R. § 1.17(m) (currently $1,700 for large entities) in order to do so.  Pursuant to 37 C.F.R. § 1.55, foreign priority claims are to be corrected by the later of four months from the actual filing date of the application or sixteen months from the filing date of the prior application.

Prior to the change in practice, the USPTO handled the correction of domestic and foreign priority claims differently.  For domestic priority claims, applicants had to file a petition for an unintentionally delayed benefit claim under 37 C.F.R. § 1.78 and pay the petition fee, and once the petition was granted, the Office would publish a corrected patent application publication.  For foreign priority claims, the Office did not previously require the petition and fee, and would not publish a corrected patent application publication.  According to the notice, the Office's rationale for the dissimilar treatment was that prior to enactment of the Leahy-Smith America Invents Act (AIA) the prior foreign patent application did not affect the effective prior art date of a U.S. patent application publication.  However, under the AIA, a U.S. patent or patent application publication may be effective as prior art as of the filing date of an earlier foreign application.  The Office has therefore concluded that "the rationale for not requiring a petition to correct an error in the application number of a foreign priority claim is no longer appropriate."

The Office's notice indicates that the change in practice with respect to correction of foreign priority claims takes effect on November 5, 2015.  The notice also indicates that any corrections to the foreign application number in a foreign priority claim that were previously accepted will not affected by the change in practice.