Can I use a certificate of mailing for all types of patent-related correspondence?

While certificates of mailing are widely applicable, they cannot be used for all types of patent-related correspondence. MPEP 512 outlines specific exceptions:

The Certificate of Mailing or Transmission procedure does not apply to the filing of a national patent application specification and drawing or other correspondence for the purpose of obtaining an application filing date.

Additionally, you cannot use a certificate of mailing for:

• Filing of an international application for patent
• Filing correspondence in an international application before the U.S. Receiving Office
• Filing a copy of the international application and the basic national fee to enter the national stage under 35 U.S.C. 371

Always check the current USPTO guidelines to ensure you’re using the correct filing method for your specific correspondence.

To learn more:

• certificate of mailing
• patent correspondence
• USPTO exceptions