/ss4-walkthrough
Online won't work? Three questions to the right path.
When the online assistant fails, SS-4 has two escalation channels: fax (≈4 business days to Cincinnati or Ogden) and mail (4–5 weeks). The right path depends on your entity type, responsible-party residency, and whether you've already pulled an EIN today. The interactive guide below collapses the SS-4 instruction tree to three yes/no questions and tells you exactly which channel applies and why. Underneath the flow, the pre-flight checker scans the inputs you'd be putting on the form so you don't walk into another rejection.
citeForm SS-4 InstructionsciteIRS Pub 1635
SS-4 escalation flow0/3
Step 1 · Entity type
What kind of entity are you applying for?
Pre-flight SS-4 checker
All inputs stay in your browser. We never send or store them.
Inputs stay in your browser. Never sent to our servers, never logged.
citeForm SS-4 Inst. — fields & validationciteIRS Pub 1635
Where SS-4 goes
| Channel | Timeline |
|---|---|
| Fax · US responsible party | ≈4 business days |
| Fax · Foreign responsible party | ≈4 business days |
| Mail · US responsible party | 4–5 weeks |
| Mail · No legal residence in the US | 4–5 weeks |
The exact fax number and mailing address depend on the responsible party's location and are set by the IRS. Get the current destination from the official Where to File Form SS-4 table on irs.gov.