April 21, 2021

A reissue application may be filed by a patent owner to correct an error in a patent. Reissue applications are useful to correct substantive errors that cannot be corrected with a certificate of correction. For example, if new art is discovered after a patent issues, a reissue application may be used to get the new prior art considered by the US Patent and Trademark Office.

In order for a reissue to be proper, the patent must be considered “wholly inoperative or partly inoperative or invalid” as a result of the error. See MPEP § 1401. Such errors may arise during the preparation and/or prosecution of an application that later became a patent.

Common bases for filing a reissue application include the following:

  • The claims are too narrow or too broad (but note that broadening reissue can be only be filed within two years of a patent’s issuance).
  • The disclosure contains inaccuracies.
  • Applicant failed to or incorrectly claimed foreign priority.
  • Applicant failed to make reference to or incorrectly made reference to prior co-pending applications.

See MPEP § 1402.

Thus, reissue applications can be a helpful tool for a patent owner to strengthen its patent portfolio before it is attacked by competitors or to prepare a patent for use in a later litigation.