What is the procedure when the USPTO cannot locate a patent or application file?

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.

When the USPTO cannot locate a patent or application file after a reasonable search, they follow the procedure outlined in 37 CFR 1.251. The key steps are:

1. The Office notifies the applicant or patentee about the unlocatable file.
2. A time period is set for the applicant or patentee to comply with the notice.
3. The applicant or patentee must respond by either:
   • Providing a copy of their record of all correspondence with the Office (except U.S. patent documents)
   • Producing their record for the Office to copy
   • Stating that they do not possess any record of the correspondence

As stated in MPEP 508.04, “37 CFR 1.251 sets forth a procedure for the reconstruction of the file of a patent application, patent, or any other patent-related proceeding that cannot be located after a reasonable search.”