IRS Fax Number for Form 1040
The IRS lists no fax line for returns. A Form 1040 or 1040-X is filed electronically or mailed to the IRS address for your state.
Where Form 1040 goes
The IRS page for filing a paper return lists a mailing address for every state, one for a return with a payment and one without, and no fax number. The same page points to IRS Free File and online fillable forms for filing electronically. Those are the two ways a 1040 reaches the IRS. A fax number you find for an IRS campus belongs to a specific unit for a specific form.
Where Form 1040-X goes
An amended return, Form 1040-X, can be filed electronically with tax software for the current tax year and the two before it, or mailed. The IRS page for the form lists no fax option. The mailing address is the one for your state on the IRS where-to-file page, in the sources below.
Faxing a reply to an IRS letter
An IRS letter about your return may carry a fax number for your reply. If it does, use it. That reply answers the letter and does not file the return. One version of Letter 12C asks for Form 8962 and your Form 1095-A; the Letter 12C guide walks through it.
To send that reply with FaxTerra, upload the pages the letter asks for, enter the fax number printed on the letter, and send. Put your name, SSN and the notice number on the cover sheet. Your delivery confirmation is a timestamped record that the IRS fax line took every page. The proof-of-filing guide covers what it does not show.
Frequently Asked Questions
What is the IRS fax number for Form 1040?
There is none. The IRS lists mailing addresses by state and electronic filing for Form 1040, and no fax number. A fax line you find for an IRS campus serves a specific form, not returns.
Can I fax my 1040 to the IRS instead of mailing it?
No. File it electronically, through IRS Free File, online fillable forms or tax software, or mail it to the address for your state.
Can I fax Form 1040-X?
No. Form 1040-X is filed electronically with tax software for the current tax year and the two prior years, or mailed to the address for your state. The IRS lists no fax option for it.
I already sent my return to an IRS fax number. Is it filed?
The IRS lists no fax line for returns, so don't count on a faxed return being filed. E-file or mail it, unless an IRS letter told you to fax it.
When do I fax the IRS about my 1040?
When an IRS notice about your return gives you a fax number for your reply. Use the number on the letter, include the notice number on your cover sheet, and keep the delivery confirmation.
More guides: IRS fax numbers directory · Can I fax my tax return? · How to fax the IRS