What is the purpose of a certificate of mailing or transmission in patent applications?
The purpose of a certificate of mailing or transmission in patent applications is to provide evidence of timely filing when correspondence is not received by the USPTO or is received late. As stated in MPEP 512:
The Certificate of Mailing or Transmission procedure does not apply to papers mailed in a foreign country.
This procedure allows applicants to prove that they submitted their correspondence on time, even if it’s delayed or lost in transit.
To learn more:
Topics:
MPEP 500 - Receipt and Handling of Mail and Papers,
MPEP 512 - Certificate of Mailing or Transmission,
Patent Law,
Patent Procedure