How to Fax IRS Forms Online

The IRS still accepts several forms and documents by fax — but not everything, and using the wrong fax number can send your paperwork to the wrong processing center entirely. Here's a plain guide to what you can fax, what you can't, and how to actually send it.

Forms the IRS Commonly Accepts by Fax

Other Fax-Eligible Situations

• IRS notices and letters — if a CP notice or letter includes a fax number and invites a faxed response, you can generally use it
• Case-specific documents — an IRS employee, auditor, or revenue officer may request supporting documents by fax for an open case

Finding the Correct Fax Number

This is the part that trips people up: many IRS forms route to different fax numbers depending on your state or situation, and these numbers can change. Rather than relying on a number from an old blog post or forum comment, always check:

• The current official instructions for your specific form on irs.gov
• The fax number printed directly on any notice or letter you received — use that number specifically, not a general one

Once you have the correct number, you can enter it directly when sending your fax — no need to guess or search for it separately.

Tips for a Clean Submission

1. Use a clean, high-resolution scan or PDF — blurry photos can make signatures and ID numbers unreadable
2. Include a cover sheet noting the form name, tax year, and your contact information
3. Double-check that forms requiring a signature (like 2848 and 8821) are signed and dated correctly — missing or improperly dated signatures are a top rejection reason
4. Keep your delivery confirmation as your proof of submission, since the IRS does not send its own fax confirmation for most forms