What is the time limit for filing a reissue application?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

There is no specific time limit for filing a reissue application. However, the two-year rule mentioned in MPEP 1403 states:

“A reissue application can be filed within two years from the grant of the original patent without any specific explanation for the delay.“

If more than two years have passed since the grant of the original patent, the applicant must provide an explanation for the delay. The USPTO will then determine if the delay was unintentional based on the explanation provided.