What does ‘unintentional delay’ mean in the context of restoring provisional application benefit?

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.

‘Unintentional delay’ is a crucial concept when seeking to restore the benefit of a provisional application. The MPEP requires:

“A statement that the delay in filing the subsequent nonprovisional application or international application designating the United States within the twelve-month period was unintentional.”

While the MPEP doesn’t provide a specific definition of ‘unintentional delay’, it generally means that the failure to meet the 12-month deadline was not deliberate. The USPTO may require additional information to determine if the delay was truly unintentional:

“The Director may require additional information where there is a question whether the delay was unintentional.”

It’s important to be prepared to explain the circumstances that led to the delay if requested.

For more information on patent procedure, visit: patent procedure.

For more information on provisional application, visit: provisional application.

For more information on unintentional delay, visit: unintentional delay.