Question 1

How long does the IRS take to fax back an EIN confirmation?

Accepted Answer

Across the EIN confirmations the IRS faxed back to FaxTerra users, the median wait was 16 days and 89% arrived within three weeks. 8% took longer than four weeks, and the slowest took 57 days.

Question 2

What if it has been more than three weeks?

Accepted Answer

By three weeks, 89% of the replies we see have arrived, and only about one in four applications still waiting after that ever gets a fax. Call the IRS Business & Specialty Tax Line at (800) 829-4933 and request a Letter 147C, which confirms your EIN. Ask for it by fax and the agent can fax it to you during the call.

Question 3

Where does this data come from?

Accepted Answer

These are anonymized timings measured by FaxTerra: the gap between a user faxing Form SS-4 (EIN application) to the IRS and the IRS faxing the EIN confirmation back, observed arriving from IRS lines in Memphis, TN and West Virginia. We count only applications faxed at least 30 days ago, so slow replies have had time to arrive, and only a confirmation that arrived on a fax number the sender already held when they filed. The figures are directional, not an official IRS service-level figure. Last updated September 17, 2026.

Question 4

Will the IRS definitely fax my EIN back?

Accepted Answer

Usually, but not always. When you apply by fax, the IRS sends the EIN assignment to the return fax number on your SS-4, and some applications never get a reply. A reply can only arrive if the IRS has a working return fax number. Fill in the "Applicant's fax number" field in the form's signature block, put the same number on your cover sheet, and keep that line active until the EIN arrives. If nothing has come back after three weeks, call the IRS Business & Specialty Tax Line at (800) 829-4933 and request a Letter 147C.

How long does the IRS take to fax back your EIN?

How long replies took

What to expect after you fax Form SS-4

Put your return fax number on the form itself

Keep that fax number reachable until the reply arrives

Call for a Letter 147C after 3 weeks

Get a fax number that catches the reply