Catalogue — REF A-1…E-2
- A-1 — EIN basics for non-residents
- A-2 — EIN vs. ITIN vs. SSN — the three numbers
- B-1 — Responsible-party rules
- B-2 — Application routes, compared
- B-3 — Form SS-4, annotated line by line
- B-4 — Reference numbers 101 and 102
- B-5 — When the responsible party changes
- C-1 — Lost CP 575 & the Letter 147C replacement
- C-2 — Wrong name or address on the CP 575
- C-3 — Closing an EIN — the IRS never cancels one
- D-1 — Form 5472 + pro-forma Form 1120
- D-2 — State tax IDs are not EINs
- E-1 — TIN matching and name control
- E-2 — How a bank verifies an EIN
- The Catalogue
- Find Your Answer
- Reference Desk
- Checklist Review
- Errata & Changes
- Enquiries (FAQ)
- Imprint & Method
- Contact — Request Slip
EIN vs. ITIN vs. SSN — the three numbers
Most EIN trouble for non-residents is one number mistaken for another. This entry is the library's decision reference in its free form: three numbers, three issuers, three different jobs.
Verified on November 4, 2026 against the IRS pages “Employer identification number” and “Individual taxpayer identification number (ITIN)” and IRS Topic No. 857, cited in full at the foot of this entry.
§ 1 —The three numbers, side by side
| Question | EIN | ITIN | SSN |
|---|---|---|---|
| Who holds it | An entity (company, partnership, trust, estate) | An individual | An individual |
| Who issues it | IRS | IRS | Social Security Administration |
| Applied for on | Form SS-4, or the IRS online EIN application | Form W-7 | Form SS-5, through the SSA |
| Its job | The entity's federal tax identification: returns, reporting, tax accounts | Federal tax processing for an individual who needs a U.S. taxpayer number but is not eligible for an SSN | The individual's U.S. social-security and tax identity |
| Needs the other? | Application names a responsible party; that party's SSN/ITIN is requested where they have one — a foreign party with neither can still be named on the non-online routes | Requires a federal tax purpose; not issued solely for banking, e-commerce, or starting a business, per IRS Topic No. 8573 | Eligibility turns on citizenship or authorised immigration status — outside this library's subject |
§ 2 —The confusions that cost time
“I need an ITIN so my company can get an EIN.”
Not as the IRS states the rules. A foreign responsible party who has neither an SSN nor an ITIN — and is not eligible to obtain one — is not required to obtain an ITIN to receive an EIN. On the paper Form SS-4, the instructions direct such an applicant on line 7b; the application then travels by fax, mail, or the international phone route rather than online.2 The detail is in REF B-1 and REF B-2.
“My ITIN is my company's tax ID.”
An ITIN identifies a person for federal tax purposes. It is not an entity number: it does not go where a form asks for the entity's EIN, and an entity cannot hold one. Conversely, an EIN never identifies the owner personally.
“An ITIN lets me work / proves my status.”
The IRS states plainly that an ITIN does not authorise work in the United States, does not provide or change immigration status, and does not qualify its holder for Social Security benefits or the Earned Income Tax Credit. It is a tax-processing number, for federal tax purposes only.3
“My ITIN is permanent.”
An ITIN that is not used on a federal tax return at least once in three consecutive tax years expires on December 31 of the third year of non-use, per the IRS.2 Renewal is on Form W-7. An EIN, by contrast, is not described by the IRS as expiring through non-use.
The decision, in one line: the entity needs an EIN; the individual needs an ITIN only when they have their own federal tax purpose and no SSN eligibility; an SSN is never applied for as part of an EIN application.
Reference Desk members receive this reference as a worked decision walkthrough — situation by situation, with the form line each answer lands on. The facts above are the same facts; the Desk adds the guided path through them. See the Reference Desk.
General information only, not tax advice. Where this page and an IRS source differ, the IRS source governs.
§Sources
- IRS, “Employer identification number” — https://www.irs.gov/businesses/employer-identification-number — consulted 2026-11-04.
- IRS, “Individual taxpayer identification number (ITIN)” — https://www.irs.gov/tin/itin/individual-taxpayer-identification-number-itin — consulted 2026-11-04.
- IRS, Topic No. 857, Individual taxpayer identification number (ITIN) — https://www.irs.gov/taxtopics/tc857 — consulted 2026-11-04.