What proof is required to show an inventor is unavailable or refusing to sign?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

When filing under pre-AIA 37 CFR 1.47, the applicant must provide proof that the nonsigning inventor is unavailable or refusing to sign. According to MPEP 409.03(d):

• For an unavailable inventor, submit a statement of facts describing the diligent efforts made to find or reach the inventor. Include documentary evidence like Internet searches, certified mail receipts, etc.
• For a refusing inventor, provide evidence that the application was presented to the inventor for signature and they refused. This can include:
• A statement detailing the circumstances of the presentation and refusal
• Documentary evidence of written refusal
• Statement of the reasons given by the inventor for refusing

The section states: Where inability to find or reach a nonsigning inventor ‘after diligent effort’ is the reason for filing under pre-AIA 37 CFR 1.47, a statement of facts should be submitted that fully describes the exact facts which are relied on to establish that a diligent effort was made.