What information must be included in a certificate of mailing for USPTO correspondence?

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.

A certificate of mailing for USPTO correspondence must include specific information to be valid. According to MPEP 512, the following information is required:

• The date of deposit or transmission
• The application number (for patent applications)
• A statement that the correspondence is being deposited with the USPS or transmitted to the USPTO
• The signature of the person depositing or transmitting the correspondence

The MPEP states:

The certificate must state that the correspondence is being deposited with the United States Postal Service with sufficient postage as first class mail, or transmitted to the Office on the date of the certificate.

Ensure all these elements are included to make your certificate of mailing valid and effective.