When can a reissue application be filed?

A reissue application can be filed when an unexpired patent is found to be defective. The key criteria are:

• The original patent must still be in force (unexpired)
• There must be a defect in the patent that needs correction

It’s important to note that the reissue process is not for extending the term of a patent, but for correcting issues in the existing patent. For more detailed information on the timing and requirements, refer to MPEP Chapter 1400, which provides a comprehensive treatment of reissue applications.

To learn more:

• reissue application timing
• unexpired patent
• patent defect correction