What evidence is required to show an inventor is unavailable or refuses to sign?

To show an inventor is unavailable or refuses to sign, the petitioner must provide substantial evidence. According to MPEP 409.03(b):

‘The fact that an inventor is unavailable or refuses to join in an application must be established by satisfactory proof… such as inability to find him or reach him after diligent effort.’

Evidence may include:

• Copies of correspondence sent to the last known address with no response
• Returned mail showing the inventor is no longer at the address
• Affidavits from people with knowledge of the inventor’s unavailability
• Documentation of attempts to contact the inventor through various means

For refusal to sign, direct evidence such as a written statement from the inventor expressing their refusal would be ideal. In the absence of such direct evidence, circumstantial evidence showing implied refusal may be considered.

To learn more:

• unavailable inventor
• refusal to sign
• evidence requirements