Tax Documents & IRS Faxing: FAQ

Where to find the right IRS fax number, what to include, and how to avoid failed transmissions.

Deep dive: How to Fax the IRS · Troubleshooting: Fix failed faxes

Can I fax documents to the IRS?
Yes, but only certain workflows accept fax (identity verification responses, notice responses, some POA workflows when instructed). Always use the fax number listed on your IRS notice or instructions.
How do I find the correct IRS fax number?
IRS fax numbers are case- and department-specific. Use the number on your letter/notice. If none is provided, call the IRS to confirm before sending.
Should I fax an original tax return (like Form 1040)?
Generally no. Original returns are usually filed via e‑file or mail unless an IRS unit specifically instructs you otherwise.
What should be in my IRS fax packet?
Single PDF: cover sheet → IRS notice/letter → your response → supporting docs. Put your name, last 4 of SSN/TIN, notice number, tax year, phone, and page count on the cover.
How can I reduce risk when faxing sensitive tax documents?
Use a trusted service with encryption in transit, avoid public Wi‑Fi, and keep the cover sheet minimal (last 4 digits only). Save confirmation receipts.
My IRS fax failed. What should I do?
Verify the destination number, resend as a clean PDF, and retry during business hours. See fax troubleshooting.
Where can I learn the full IRS faxing process?
See How to fax the IRS.