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It depends on which side of the USPTO you are dealing with. For trademarks, no: the USPTO stopped accepting faxed trademark documents, and filings are electronic only. For patents, yes: the Office of Petitions still accepts petitions and related papers by fax to its published fax lines.
This is general information, not legal advice.
| What you are filing | Fax accepted? | The right channel |
|---|---|---|
| Trademark applications, responses, office-action replies | No | Electronic filing only, through the USPTO's trademark system |
| Trademark Trial and Appeal Board matters | No | TTAB Center, the board's electronic filing platform |
| Patent petitions and related requests | Yes | Office of Petitions central fax: 571-273-8300 |
| Urgent petitions to withdraw from issue or defer issuance | Yes | Direct line 571-273-0025, marked "Special Processing Submission" |
| PCT documents to the USPTO | Mostly yes | Central fax, except certified documents, priority documents, and secrecy-order material |
The USPTO ended a temporary exemption and stopped accepting trademark documents by fax effective July 1. Electronic filing had already been mandatory since early 2020, when the office reported that only a tiny fraction of trademark applications were still arriving on paper. The fax exemption existed to ease filers through an identity-verification transition, and once nearly everyone had verified, the office shut the fax window.
The USPTO's own explanation is refreshingly blunt: faxes reproduce poorly in their systems and need time-intensive manual processing, which delays examination and stretches wait times for everyone. If you cannot access the online filing system on your deadline, the office points you to mail or hand delivery with a petition to accept paper, plus a coversheet certifying the filing date. Fax is not on the list of fallbacks.
Because petitions are different from applications. A petition asks the office to do something unusual: revive an abandoned application, withdraw a patent from issue at the last minute, defer issuance, record an assignment. These are time-sensitive, one-off requests where a fax to a specific desk can still be the fastest reliable route. The Office of Petitions publishes its fax numbers on uspto.gov for exactly this purpose.
Note the split within the split: ordinary petitions go to the central fax number, but urgent petitions where issuance is imminent, like a petition to withdraw from issue, go to a separate direct line. Send those to the central number and they sit in the general queue, which defeats the point of marking them urgent. When patent attorneys say "know which fax number," this is what they mean.
Anything under a secrecy order, for starters: applications subject to national-security secrecy orders may not be faxed at all, and that rule is explicit in the USPTO's own filing guidance. Certified documents, including certified priority documents, also cannot go by fax for PCT purposes, since the whole point of a certified copy is the physical certification. And correspondence that requires an original signature with formal evidentiary weight belongs on paper or through the electronic system, not on a thermal printout.
Electronically, whenever the option exists. The USPTO's electronic systems timestamp your filing the moment it is submitted, return an acknowledgment you can save, and route the document to the right examiner or board without a human retyping anything. Fax survives as the channel for the narrow cases where the electronic system cannot help: the urgent petition, the after-hours filing to a specific office, the paper that does not fit any online form. Use it for those, and use the portal for everything else.
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