The IRS does not accept faxed tax returns — but fax still plays an important role in tax season. Learn exactly which forms the IRS accepts by fax, when faxing is faster than mailing, and the one exception where the IRS may ask you to fax documents.
Frequently Asked Questions
Can I fax my tax return (Form 1040) to the IRS?
No. The IRS does not accept Form 1040 tax returns via fax under any standard circumstance. You must e-file through tax software or mail a paper return to the correct IRS processing center.
Can I fax my amended tax return (Form 1040-X)?
No. There is no IRS fax number for Form 1040-X. Amended returns must be filed electronically (for tax years 2021 and later) or mailed to the appropriate IRS Service Center.
What tax documents CAN I fax to the IRS?
The IRS accepts faxes for several specific forms, including Form SS-4 (EIN application), Form 2848 (Power of Attorney), Form 8821 (Tax Information Authorization), Form 4506-T (transcript request), and Form 2553 (S-Corp election). See our [complete IRS fax numbers guide](/blog/taxes-irs-fax-numbers/).
Does the IRS ever ask taxpayers to fax documents?
Yes — during an audit. If you receive an IRS audit notice (such as a CP75 or Letter 566), the notice includes a specific toll-free fax number for submitting supporting documents. This is not the same as faxing a tax return.
Can I fax a tax extension (Form 4868) to the IRS?
No. Form 4868 (Application for Automatic Extension of Time to File) cannot be faxed. File it electronically through tax software or mail it before the April deadline.