Can I use a Certificate of Mailing or Transmission for electronically filed documents?

Yes, you can use a Certificate of Transmission for documents filed electronically through the USPTO’s Electronic Filing System (EFS-Web). The MPEP provides a suggested format for a Certificate of EFS-Web Transmission:

I hereby certify that this correspondence is being transmitted via the U.S. Patent and Trademark Office electronic filing system (EFS-Web) to the USPTO on [Date].

However, it’s important to note that EFS-Web submissions have their own timestamp system. According to 37 CFR 1.6(a)(4):

Correspondence submitted to the Office by way of the Office electronic filing system will be accorded a receipt date, which is the date the correspondence is received at the correspondence address for the Office set forth in § 1.1 when it was officially submitted.

This date can be a Saturday, Sunday, or federal holiday within the District of Columbia. The certificate can provide an additional layer of documentation for your submission date, but the EFS-Web timestamp is generally considered authoritative for determining the receipt date of electronic submissions.