IRS Audit Fax Number: Where to Send Your Response

Where to find your IRS audit fax number

Your IRS audit fax number is printed on the notice the IRS mailed you, usually in the response section near the bottom or on the tear-off reply page. There is no single national fax line for audits. Exam correspondence runs through several IRS campuses, and each one uses its own numbers.

That surprises people. They search for one number, land on a five year old forum post, then send records with a Social Security number to a line that has nothing to do with their case.

Look for one of these phrases on your letter: "Fax your reply to," "Send your response to the fax number shown," or a number printed next to the examiner's name and badge ID. On a correspondence exam the number sits beside the response form. On an office or field exam it is often the assigned examiner's direct line.

If the paper notice is lost, do not guess. Call the phone number on any IRS correspondence for the same tax year, or sign in to your account on the IRS audits page for case details. The agency does not publish a general audit fax directory, so third party lists go stale within months.

One more check before you send. Some IRS letters say plainly that a response must be mailed or uploaded, not faxed. Follow that instruction. A faxed reply to a mail-only address can sit unmatched to your file while your deadline runs out.

Match the number to the notice you actually received

Different IRS letters route to different fax lines, so the notice number in the top right corner decides where your response goes. Find that code first, then find the fax number underneath it.

Here is what the common ones mean:

• CP2000. A proposed change from the Automated Underreporter program. It is not a formal audit, though it certainly reads like one. The included response form carries its own fax number. The IRS explains the CP2000 process here.
• CP75 and CP75A. A refund hold tied to the Earned Income Tax Credit or a similar credit. These ask for Form 886-H documents such as school or medical records.
• Letter 566. The opening letter for a correspondence exam. It lists the specific line items under review.
• Letter 525 or Letter 915. The 30 day letter, usually paired with an examination report on Form 4549.
• Letter 2205-A. A request to schedule an office or field exam. Replies normally go straight to the examiner named on the letter.
• Letter 3219. The statutory notice of deficiency, often called the 90 day letter. A Tax Court petition cannot be faxed to the IRS, and that deadline cannot be extended.

Planning to bring in a representative? Form 2848 has its own fax numbers listed in the form instructions, and they are not the same as your exam fax line. Send the power of attorney where the form says, then include a copy in your audit packet so the examiner sees who speaks for you.

What to include in your audit response

Send the response form from the notice first, then a signed explanation letter, then supporting records in the order your letter references them. Order matters more than volume.

The examiner is matching your pages against a list of questioned items. Your job is to make that match obvious in under a minute of their time.

1. The response form or reply page from the notice, signed and dated.
2. A short letter, one page if you can manage it, answering each questioned item by its number on the notice.
3. Supporting records, labeled to match those item numbers.
4. Form 2848 or Form 8821 if someone is representing you.

Legibility decides more cases than people expect. Fax converts pages to black and white at modest resolution, so a faint thermal receipt can arrive as a gray smear. Photograph records in flat daylight, or scan at 200 dpi and above, and always check the preview before you send.

Do not send originals. Do not send more than the notice asks for, either. Extra tax years, unrelated accounts, and stray statements can widen the scope of an exam that was narrow to begin with.

Build a cover sheet the examiner can act on

A working IRS fax cover sheet shows your name, taxpayer identification number, notice number, tax year, total page count, and a daytime callback number. Nothing else is required, and nothing else helps.

Copy this layout:

Count your pages twice. If a transmission drops at page nine of fourteen, the examiner needs the total on the cover sheet to know something is missing. A footer reading "Page 3 of 14" on each sheet helps even more.

Skip the pleasantries and the long explanation on the cover page. Put your argument in the signed letter, where it belongs in the file.

How to fax an audit response from your phone

You can fax an IRS audit response from a phone in about a minute, with no machine and no landline. Faxend sends from the iPhone app or from faxend.com/send in any browser.

Two details matter more than usual with tax documents. The first is encryption. Faxend protects files with AES-256 in transit and at rest, which is the bar you want when the pages carry your Social Security number and a full year of income detail.

The second is cost. The Basic plan is $2.99 one time for five pages, with 30 days of credit and no account required, which fits a one-shot CP2000 reply. If your packet runs long, or you expect several rounds of correspondence, the $9.99 monthly Standard plan covers 20 pages and keeps a send history you can point to later. Pro at $19.99 adds unlimited pages plus a dedicated inbound number, worth it when the examiner wants to fax you back. Current details sit on the pricing page.

Never sent a fax from a phone before? Our walkthrough for sending a fax from iPhone covers the screens in order. If you would rather compare options first, the roundup of the best fax apps for iPhone in 2026 lays out the tradeoffs, and there is a separate look at fax apps that skip the subscription.

Under the hood these sends travel over T.38 fax over IP, which is why a phone can reach a government fax line that has never touched the internet.

Fax, the IRS upload tool, or certified mail

Fax is the fastest channel that still leaves you a timestamped receipt, though the IRS Document Upload Tool now accepts responses to many notices. Choose based on what your specific letter allows.

Method	Typical speed	Proof you responded	Worth knowing
Online fax (Faxend)	30 to 60 seconds per page	Transmission confirmation with timestamp	Works from a phone, but the number must come from your notice
IRS Document Upload Tool	Immediate	On-screen confirmation and receipt	Only for notices showing an access code or upload link
Certified mail, return receipt	3 to 7 days	Tracking plus signed receipt	Postmark date is what counts for a deadline
Standard first class mail	3 to 10 days	None	A poor choice inside 10 days of a deadline
Taxpayer Assistance Center	Same day	Date-stamped copy	Appointment required, and availability varies by city

The upload tool has expanded a lot, and for eligible notices it removes the guesswork about which fax line is correct. Check the IRS Document Upload Tool page to see whether your notice qualifies before you fax.

Plenty of people do both. Upload the packet, then fax the same packet, then note both confirmations in the file. It costs a few dollars and removes an argument you would otherwise have six months from now.

Deadlines, and how to prove you responded

Most IRS audit notices give you 30 days from the date printed on the letter, not 30 days from the day it landed in your mailbox. Read the deadline line before you read anything else.

Mail delays eat into that window regularly. If the notice reached you a week late, you may have 20 usable days, and a fax that arrives on day 29 still counts as timely.

Keep three things after you send:

• The transmission confirmation, showing the date, time, destination number, and page count.
• A PDF or photo set of the exact pages you sent, in the exact order.
• A one-line note of who you spoke to at the IRS, if anyone, and when.

Hold that file for at least three years. The general assessment period is three years, and it stretches to six when income is substantially understated, so a longer retention habit costs you nothing.

If the deadline is close and your records are not ready, respond anyway. Send a partial reply with what you have, state clearly which items are still being gathered, and ask for additional time in writing. Silence gets treated as agreement with the proposed change, and that is how a $900 question becomes a $9,000 assessment.

Letter 3219 is the exception to all of this. Once the statutory notice of deficiency issues, the 90 day clock is set by law, and no examiner can move it.

Mistakes that stall an audit response

Most delayed audit responses fail for boring reasons, not complicated ones. These are the repeat offenders.

• Using a fax number from a search result. The number on your notice is the only one tied to your case file.
• Leaving out the response form. Without it, your documents may not route to the right examiner.
• Faxing a Tax Court petition. That filing goes to the Court, not the IRS, and not by fax.
• Angled phone photos. Skewed pages crop badly and arrive unreadable at the other end.
• No identifier on interior pages. Separated pages without a TIN get thrown away.
• Dumping every record you own. Volume without an index reads as disorganization, and it invites more questions.
• Assuming silence means resolved. Correspondence exams often take 30 to 90 days to acknowledge. Follow up, in writing.

Get the number right, keep the packet tight, and save the receipt. That covers almost everything that goes wrong. Faxley keeps these IRS guides current as the agency shifts channels, so check back before your next notice arrives.

Frequently asked questions

Can I fax my IRS audit response from my phone?

Faxend sends an audit response from your iPhone in about a minute, and the first send is $2.99 with no subscription. Use the fax number printed on your notice rather than one from a search result.

Is there one IRS fax number for all audits?

No. The IRS routes exam correspondence through several campuses, and each notice carries the fax number assigned to that case. Always read the number off your own letter.

What if my notice does not show a fax number?

Some IRS letters ask for mail or the Document Upload Tool instead. Follow the instruction on the notice, since a faxed reply to a mail-only case can go unmatched to your file.

How long does the IRS take to reply after I fax?

Correspondence exams commonly take 30 to 90 days to acknowledge a response. If you hear nothing after 60 days, follow up in writing and reference your transmission confirmation.

Do I need a cover sheet for an IRS fax?

Yes, and keep it short. Your name, taxpayer identification number, notice number, tax year, total page count, and a daytime phone number are enough.

Can I fax Form 2848 with my audit response?

Include a copy of Form 2848 in the packet so the examiner knows who represents you. Also send the original to the fax number listed in the Form 2848 instructions, which is a different line.