How does the USPTO determine if a delay in filing a reissue application was unintentional?

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.

The USPTO evaluates the unintentional nature of delays in filing reissue applications on a case-by-case basis. According to MPEP 1403:

“In determining whether a delay in filing a reissue application was unintentional, the examiner should make an inquiry as to whether or not the delay was in fact unintentional.“

Factors considered may include:

• The length of the delay
• The reasons provided for the delay
• Any evidence of diligence in attempting to file the reissue
• The overall circumstances surrounding the delay

Applicants should provide a detailed explanation of the reasons for the delay, including any supporting documentation, to help the USPTO make an informed decision.