Fax Form 637 to the IRS — excise tax registration
As of the December 2025 revision, Form 637 (Application for Registration for Certain Excise Tax Activities) can be faxed to the IRS Excise Operations Unit at 855-887-7735 — the number is published in the Where To Apply section of the form itself. Mailing to Cincinnati remains available as an alternative.
Earlier revisions listed no fax channel, and stale third-party pages still say fax is unavailable — the current form text is the controlling source. Upload your completed, signed Form 637 and we transmit it with a dated delivery report for your records.
Fax Form 637 now — $2.49Where this form faxes
| Scenario | IRS fax number |
|---|---|
| All applicants (Excise Operations Unit, Cincinnati) | 855-887-7735 |
IRS fax numbers change without notice. We re-verify our routing table against the current IRS form instructions, and the exact number your document was sent to is printed on your transmission report.
Numbers last verified against IRS sources: 2026-07-19 · Official IRS source
Deadline
Register before engaging in the excise activity — reviews commonly take 60–120 days.
Frequently asked questions
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