How we verify IRS fax numbers

IRS fax numbers change without notice, and outdated numbers circulate widely online. That is the single biggest risk in fax filing — a fax to a dead line silently misses your deadline. Our process:

Every number in our routing table is taken from a primary IRS source: current form instructions, IRS.gov “Where to File” charts, official IRS newsroom releases, or the form PDF itself — never from third-party blogs.
Each form page links to the official IRS source we used, so you can check it yourself.
The full table is re-verified against those sources on a schedule; the date of the last verification is printed on every form page (currently: 2026-07-19).
If we cannot confirm a number in a primary source, we say so on the form page and do not auto-send that form — we would rather lose the sale than misroute your filing.
The exact number your fax was sent to is printed on your transmission report.

What we are — and what we are not

HORIZANCE Fax is operated by Horizance LLC. We are a fax transmission service: we deliver the documents you send, to the IRS number that matches the routing rules published by the IRS.

We are not affiliated with the IRS and we do not provide legal or tax advice. Whether a given form is right for your situation is a question for your tax professional; whether it reaches the right IRS fax line is ours.

Contact

Questions, corrections, or a number you believe is out of date? Write to hello@horizance.com — reports about stale IRS numbers get priority handling.