What happens if the last-known address of an unavailable inventor is invalid?

If the last-known address of an unavailable inventor is invalid, the petitioner must make a diligent effort to find a valid address. According to MPEP 409.03(b):

‘If the last known address of the nonsigning inventor(s) is invalid, petitioner must state what efforts were made to find a current address.’

This means the petitioner should document their attempts to locate the inventor, which may include searching public records, contacting former employers, or using people-finding services. If all efforts fail, this should be clearly stated in the petition.

To learn more:

• inventor address
• diligent effort
• petition requirements