Reissue Patent Law and Legal Definition

A reissue patent is a patent issued by the U.S. Patent and Trademark Office (PTO) to correct a significant error in an already issued patent. A reissue patent may be issued for utility, design, or plant patents. A reissue patent does not change the term of the original patent. It only corrects the error in the original patent. Only patent holders can file reissue applications.

In the U.S., patent holders may even request to broaden the scope of their invention by filing a reissue application. However, such application for broadening the scope of invention must be filed within 2 years from grant of the patent. The applicant has to pay a fee for reissue patents.

A patent will be reissued only if there are significant errors in the original patent. Typographical, editorial or clerical errors, and spelling and grammar mistakes will not be considered as significant errors.

The following are a few examples of common errors that are considered significant:

1. Too narrow or too broad claims. However, reissue applications to broaden the scope must be filed within two years from the grant of the original patent.

2. Inaccuracy in specification disclosures.

3. Incorrect claims or failure to claim foreign priority.