IRS Fax Number for Form 1040 and How to Send It

The IRS fax number for Form 1040

There is no IRS fax number for Form 1040. The IRS does not accept original individual income tax returns by fax, and a faxed 1040 will not enter the processing system.

This catches people out every filing season. Search results and forum threads list numbers that look official. Most of them belong to a CAF unit, the EIN operation, or a private tax prep firm. None of those groups process returns.

Your two filing options are electronic filing and paper mail. Both are covered further down this page.

The same rule covers Form 1040-X, the amended return. You can e-file a 1040-X for recent tax years, or you can mail it. Fax is not on the list.

The reason is mechanical, not bureaucratic. Returns move through scanning and validation pipelines built around specific paper stock and image quality. Fax output does not meet that bar. Signature and attachment rules add another layer.

During 2020 and 2021 the IRS opened temporary fax lines for a few refund claims, including Form 1139 and Form 1045. Those lines closed. Anything you read about faxing returns from that stretch is out of date now.

This guide is maintained by Faxley and rechecked against current IRS instructions each season.

IRS forms and notices you can fax

The IRS accepts fax for a short list of forms and for most notice responses. The table below covers the ones individual taxpayers hit most often.

Form or document	IRS fax number	Notes
Form SS-4, EIN application, US applicant	855-641-6935	EIN faxed back in about four business days
Form SS-4, international applicant	855-215-1627 from inside the US 304-707-9471 from outside the US	A phone option also exists
Form 2848 or Form 8821, Memphis CAF unit	855-214-7519	Correct unit depends on your state
Form 2848 or Form 8821, Ogden CAF unit	855-214-7522	Correct unit depends on your state
Form 14039, Identity Theft Affidavit	855-807-5720	Online submission is also available
CP2000 or other notice response	Printed on the notice itself	Never substitute a generic number
Letter 12C, missing Form 8962	Printed on the letter	Routes to the team holding your file
Audit or examination documents	Supplied by your examiner	Ask for it in writing

Two details matter here. The CAF unit for a power of attorney depends on the state on the form, and the split appears in the IRS authorization rules. Send it to the wrong unit and it gets rerouted, which costs weeks.

IRS fax numbers also change. Check any number against the current form instructions or against the notice in your hand before you send. The Where to File page for Form SS-4 governs EIN applications. Identity theft numbers live on the IRS identity theft affidavit page.

Notice responses are the largest category by volume. A CP2000 proposes changes to your return based on data from employers and banks. Its fax number sits near the top of the first page. That number routes to the unit already holding your case file, which is exactly why a generic number will not do.

Transcripts are a common miss. The IRS stopped faxing tax transcripts to individuals back in 2019 as an identity theft control. Request transcripts through your online account or by mail instead.

How to file Form 1040 when fax is off the table

File Form 1040 by e-file or by mail. E-file is faster and cheaper, and it flags a rejection within hours instead of weeks.

Most filers use tax software or a paid preparer. The IRS also runs Free File for taxpayers under an income threshold that shifts each year. Refunds on e-filed returns with direct deposit usually land in under three weeks.

Paper filing still works fine. The mailing address depends on your state and on whether a payment is enclosed, so the same state has two different addresses. The Where to File page lists every combination.

Send paper returns by certified mail with return receipt. Under the timely mailing rule, a return postmarked by the deadline counts as filed on time even if it arrives weeks later. That receipt is your proof.

Paper processing runs slow. Six to eight weeks is normal, longer at peak. Need more time to file at all? Form 4868 buys an automatic extension to file, though it does not extend the time to pay.

How to fax documents to the IRS from your phone

Photograph the pages, confirm the fax number on your IRS notice, add a cover sheet, and send. Faxend handles all four steps from an iPhone, and a short response usually goes through in under a minute.

Fax survives here because it lands on equipment the IRS already trusts. Services carry the call over T.38, a protocol that moves fax traffic across IP networks while preserving the handshake the receiving machine expects. You get the old reliability without owning a machine.

Cost is worth a line. The Faxend Basic plan is $2.99 for one send of up to 5 pages, with no account and no recurring charge, and the credit stays live for 30 days. Monthly plans sit on the pricing page if you send often. You can start from a browser at faxend.com/send, or from the iPhone app on the App Store.

Sending tax records means sending your SSN. Every Faxend plan is HIPAA-ready with AES-256 encryption in transit and at rest, which is the same protection level applied to medical records. For a longer walkthrough of the capture and send flow, see how to send a fax from an iPhone.

What belongs on your IRS fax cover sheet

An IRS fax cover sheet needs six fields. Your full name, your taxpayer ID, the tax year, the notice or letter number, the page count, and a callback phone number.

Leave any of them off and your pages can sit unmatched. The IRS receives an enormous volume of loose paper. A fax with no identifying detail is just a stack with no home.

Clerks match documents to case files using the notice number and the taxpayer ID. Those two fields carry the most weight, so put them near the top and make them legible.

Write the taxpayer ID the way the notice shows it. On a joint return, use the SSN of the primary filer listed first. For a business matter, use the EIN.

Keep the cover sheet to one page. One plain line of context is enough. Something like "Response to CP2000 dated March 14, tax year 2025, 6 pages including this cover" does the job. No essay required.

Count your pages and print the count. If the IRS receives 4 of 6 pages, the count tells them something dropped. That alone can spare you a second notice.

How to confirm the IRS received your fax

The IRS sends no acknowledgment when a fax arrives, so your transmission receipt is the only proof you will hold. Save it the second the send completes.

A usable receipt shows the destination number, the date, the time, the page count, and a success status. Screenshot it. Store it with your tax records for that year, ideally in cloud storage rather than buried in a camera roll.

Give the IRS at least 30 days before following up. Notice responses often take longer than that. Calling early rarely moves anything, and hold times during filing season are brutal.

When you do call, use the phone number on the notice rather than the general help line. Have the receipt open. Being able to say "sent to 855-807-5720 on April 2 at 10:14 a.m., 6 pages, confirmed" changes the whole conversation. Without it, you are asking an agent to take your word.

Keep records at least three years from the filing date. Seven is safer when the matter touches unreported income or worthless securities, since the assessment window stretches in those cases.

Mistakes that sink IRS faxes

Most failed IRS faxes trace back to five errors, and every one of them is avoidable in under a minute of checking.

• Using a number from a search result. IRS fax lines are routed by unit and by case. The number on your notice is the only one that reaches your file.
• Faxing something the IRS will not take. Original returns, amended returns, and payments each need a different channel.
• Skipping the cover sheet. Unidentified pages get set aside, and nobody calls to tell you.
• Sending a dark or crooked scan. Fax transmission drops detail. If a page is hard to read on your screen, it will be worse on theirs.
• Discarding the receipt. Without it you cannot prove the send date, which matters most when a response deadline is in play.

One more point worth stating plainly. Deadlines on IRS notices usually run from the notice date, not from the day the envelope reached your mailbox. Mail transit eats into that window before you even open it. Fax is often the only channel left that still fits.

If you are working from a phone and do not want a monthly plan, our roundup of fax apps for iPhone without a subscription compares the pay per fax options side by side. For the wider field, including tools built for teams, see the best fax apps for iPhone in 2026.

Frequently asked questions

Can I fax my Form 1040 to the IRS?

No. The IRS does not accept original Form 1040 returns by fax. File electronically or mail the return to the address listed for your state.

Can I fax IRS documents and notice responses from my phone?

Faxend sends IRS notice responses and supporting documents from your iPhone in about a minute, with no subscription needed for the first send. Use the fax number printed on your IRS notice rather than a general number.

What is the IRS fax number for Form 2848?

Form 2848 goes to one of two CAF units. Memphis uses 855-214-7519 and Ogden uses 855-214-7522. Which one applies depends on the state shown on the form.

Is there an IRS fax number for an EIN application?

Yes. Applicants in the 50 states or DC fax Form SS-4 to 855-641-6935, and the IRS faxes the EIN back in about four business days.

Does the IRS confirm that it received my fax?

No. The IRS sends no acknowledgment for incoming faxes. Your transmission confirmation is the only proof, so save it with your tax records for that year.

How long should I wait after faxing the IRS?

Allow at least 30 days before following up on a notice response. When you call, use the phone number printed on the notice and keep your fax confirmation open.