Question 1

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

Accepted Answer

Across EIN/SS-4 confirmations the IRS faxed back to FaxTerra users, the median time was about 17 days — roughly two weeks. 87% arrived within three weeks. A small share took longer than a month, with the slowest observed at 72 days.

Question 2

Why does it sometimes take more than a month?

Accepted Answer

IRS fax-back times vary with workload and how the application is routed. The replies cluster tightly: 87% of the confirmations we see arrive within three weeks, and very few arrive after that. So if three weeks have passed with nothing, waiting longer usually does not change the outcome. Call the IRS Business & Specialty Tax Line at (800) 829-4933 and request a 147C verification letter, which they can fax to you during the call.

Question 3

Where does this data come from?

Accepted Answer

These are real, 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. To avoid skewing toward fast replies, only applications faxed at least 30 days ago are counted, and only a confirmation that arrived on a fax number the sender already held when they filed. It is directional, not an official IRS service-level figure.

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 most confirmations we see arrive within two to three weeks. A real share never arrive at all. The most common reason is that no working return fax number reached the IRS, so 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 for at least a month after you send. If nothing has come back after about three weeks, call the IRS Business & Specialty Tax Line at (800) 829-4933 and ask for a 147C verification letter. Keep your fax number active either way, because the 147C comes back by fax as well.

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

How long replies actually 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

Nothing after about 3 weeks? Call for a 147C letter

The mailed CP-575 is separate

Get a fax number that catches the reply