How does the USPTO handle correspondence with a Certificate of Mailing or Transmission?

The USPTO has specific procedures for handling correspondence with a Certificate of Mailing or Transmission:

1. All papers received by mail are date stamped with the actual date of receipt, regardless of any Certificate of Mailing.
2. For papers with a Certificate of Mailing or Transmission, the date on the certificate is used to determine if the paper was filed within the period for reply.
3. If the paper is received within the period for reply, the actual receipt date is used for all purposes.
4. If the paper is received after the period for reply, but the certificate date is within the period, the paper is considered timely filed. In this case, a notation is made next to the ‘Office Date’ stamp indicating the certificate date (e.g., ‘C of Mail 11/10/97’).
5. For facsimile transmissions, the date stamped is the date the complete transmission is received, unless that date is a Saturday, Sunday, or Federal holiday within the District of Columbia, in which case the date stamped will be the next succeeding business day.
6. For EFS-Web submissions, the receipt date is the date the correspondence is received at the USPTO’s correspondence address when it was officially submitted, which can include weekends and holidays.

The MPEP states: “The date indicated on the Certificate of Mailing or of Transmission will be used by the Office only to determine if the paper was deposited in the United States Postal Service, transmitted by facsimile or transmitted via EFS-Web within the period for reply.”