Fax your reply to an IRS notice — CP162, CP2000, Letter 12C and more

Many IRS notices can be answered by fax — and when a response window is 21 or 30 days, fax is the only channel that gives you a same-day, timestamped proof of response. The correct fax number is printed on the notice itself, usually in the top corner of page 1 or on the response stub — there is no universal number, it differs by campus and office.

Pick “Reply to an IRS notice” in our send form, type in the fax number from your letter, upload your response as a PDF, and we transmit it with a cover sheet and email you the transmission report. Penalty notices for partnerships and S corporations (CP162, CP162A, CP162B) are a typical case: a reasonable-cause abatement letter faxed within the 21-day window, with the notice stub on top.

The CP2000 series is the exception where the IRS publishes its fax numbers up front — seven of them, one per processing unit, listed below. Use the one for the unit named on the top left of your notice; they are not interchangeable.

If your notice lists only a mailing address, fax is not an option for that notice — respond by mail.

Fax IRS notice replies (CP162, CP2000 …) now — $2.49

Where this form faxes

ScenarioIRS fax number
Most noticesprinted on your notice — top corner of page 1 or the response stub
CP2000 series — Andover, MA877-477-9485
CP2000 series — Atlanta, GA877-477-0967
CP2000 series — Austin, TX877-477-0583
CP2000 series — Fresno, CA877-477-0962
CP2000 series — Holtsville, NY877-477-9599
CP2000 series — Ogden, UT877-477-9640
CP2000 series — Philadelphia, PA877-477-9602

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

Deadline

The response date printed on your notice — 21 days for CP162-series penalty notices, typically 30 days for a CP2000.

Frequently asked questions

Yes. CP162-series notices assess late/incomplete filing penalties on partnerships and S corporations, and a penalty-abatement request (first-time abatement or reasonable cause) can be faxed to the number printed on the notice. Include the notice stub, the tax period, and your explanation — and keep the transmission report as proof you met the 21-day window.

The IRS publishes seven, one per unit: Andover 877-477-9485, Atlanta 877-477-0967, Austin 877-477-0583, Fresno 877-477-0962, Holtsville 877-477-9599, Ogden 877-477-9640 and Philadelphia 877-477-9602. They are not interchangeable — send your reply to the unit shown on the top left of your own notice. A response faxed to the wrong unit may never reach your case file.

Letter 12C (missing return information), CP2000/CP2501 proposed-change responses, CP162-series penalty responses, examiner document requests (IDRs) and most correspondence-audit letters that print a fax line. The rule is always the same: use the exact number on your letter.

Yes, when the examiner requests or permits it — use the fax number the examiner or the information document request (IDR) provides.

The response page or contact stub from the notice, the notice number and tax year on every page, your explanation and supporting documents — and keep the fax confirmation with your records.

Yes: if you received an IRS notice about suspected identity theft, respond to the number/address on that notice rather than the general 855-807-5720 line.

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