The decision rule fits in one sentence: an EIN is for a business entity, an SSN is for individuals authorized to work in the U.S., and an ITIN is for individuals with U.S. tax obligations who are not eligible for an SSN. All three are 9-digit tax IDs, but they come from different agencies, serve different purposes, and are not interchangeable. Many non-residents need two of them — typically an EIN for their company plus an ITIN for themselves.
The 3-Way Comparison
| EIN | ITIN | SSN | |
|---|---|---|---|
| Full name | Employer Identification Number | Individual Taxpayer Identification Number | Social Security Number |
| Issued by | IRS | IRS | Social Security Administration |
| Issued to | Business entities, trusts, estates | Individuals not eligible for an SSN | U.S. citizens, permanent residents, noncitizens authorized to work |
| Application form | Form SS-4 | Form W-7 | Form SS-5 |
| Format | XX-XXXXXXX | 9XX-XX-XXXX (always starts with 9) | XXX-XX-XXXX |
| Purpose | Business tax filings, payroll, banking | Federal tax administration for individuals | Employment, taxes, Social Security benefits |
| Authorizes work | n/a (identifies a business, not a person) | No | Yes |
| Expiration | Never | After 3 consecutive years unused on a return | Never |
| Cost from the government | Free | Free | Free |
| Processing time | Instant online; phone same call; fax ~4 days; mail ~4–5 weeks | ~7 weeks by mail; 9–11 weeks peak season or from abroad | Varies; typically ~2–4 weeks after SSA approval |
Two clarifications the table can't fully carry:
- Work authorization belongs to the SSN column alone. An ITIN is for U.S. tax administration only. An ITIN does NOT authorize you to work in the United States, does NOT confer or change immigration status, and does NOT entitle the holder to Social Security benefits. The SSA — not the IRS — determines who is authorized to work.
- The EIN sits in a different category entirely. It identifies a company, not a human. Comparing it to an SSN is like comparing a company registration number to a passport.
Which Tax ID Do You Need? By Scenario
Non-resident founder of a U.S. LLC
You need an EIN for the LLC — it is required for the company's IRS filings (a foreign-owned single-member LLC files Form 5472 annually) and for the business bank account. You likely also need an ITIN for yourself if you have personal U.S. filing obligations, such as filing Form 1040-NR or claiming tax treaty benefits. See LLC formation for foreign nationals for the full sequence.
Foreign Amazon or e-commerce seller
The selling entity needs an EIN — Amazon's tax interview collects it on Form W-8BEN-E for foreign entities. The owner may additionally need an ITIN when personal U.S. tax filings or treaty claims come into play. Start with how to get an EIN as a non-US resident.
Spouse of a U.S. taxpayer
If you are married to a U.S. citizen or resident and have no SSN, you need an ITIN to be included on a joint federal return or claimed for filing purposes. The application is Form W-7, filed with the tax return.
Foreign investor in U.S. real estate
You need an ITIN for rental income reporting on Form 1040-NR and for FIRPTA withholding when you sell. If the property is held through an LLC, the LLC also needs an EIN.
U.S. employee
If you are a U.S. citizen, permanent resident, or noncitizen with work authorization, you need an SSN, issued by the Social Security Administration via Form SS-5 — not by the IRS. If you are eligible for an SSN, the IRS will not issue you an ITIN; the SSN takes precedence.
Quick decision table
| Your situation | EIN | ITIN | SSN |
|---|---|---|---|
| Forming a U.S. LLC (non-resident owner) | Yes | Often | No |
| Selling on Amazon via a foreign or U.S. entity | Yes | Sometimes | No |
| Spouse/dependent on a U.S. tax return | No | Yes | No |
| U.S. rental property owner (non-resident) | If held in an LLC | Yes | No |
| Authorized to work in the U.S. | Only if you also own a business | No | Yes |
| Opening a business bank account | Yes | No (personal accounts differ) | No |
For personal banking, some U.S. banks accept an ITIN on individual accounts.
Can You Have More Than One?
ITIN + EIN: yes, and it's common. The ITIN is your personal tax ID; the EIN is your company's. A non-resident founder filing a 1040-NR while running a Delaware LLC holds both, and the IRS expects exactly that. The deeper dive: EIN vs ITIN: which do you need.
ITIN + SSN: no. The two are mutually exclusive. If you become eligible for an SSN — for example, after receiving work authorization — you apply to the SSA via Form SS-5, stop using the ITIN entirely, and notify the IRS in writing so your tax records are combined under the SSN. Your filing history and payments carry over in IRS records once the accounts are merged; the ITIN itself is simply retired. Using both numbers simultaneously causes processing problems.
Multiple EINs: one per entity. Each separate legal entity gets its own EIN. One person can be the responsible party for several entities, though the IRS issues at most one EIN per responsible party per day.
How You Get Each One
| Where | How | Timeline | |
|---|---|---|---|
| EIN | IRS | Online (needs SSN/ITIN), or Form SS-4 by phone +1-267-941-1099, fax, or mail | Instant to ~5 weeks — see how to get an EIN |
| ITIN | IRS | Form W-7, normally attached to a federal return; via mail, a Certified Acceptance Agent, or an IRS TAC appointment | ~7 weeks by mail; a CAA prepares and verifies documents in 5–10 business days — see what is an ITIN |
| SSN | Social Security Administration | Form SS-5 with proof of identity, status, and work authorization | Set by the SSA; check ssa.gov for current processing |
All three are free from the issuing agency. Paid services exist for the two IRS numbers because the applications fail often — wrong W-7 reason codes, document certification problems, SS-4 phone queues from abroad. As an IRS Certified Acceptance Agent, itin.net handles ITIN applications ($497) and EINs for non-residents ($297) with a 100% money-back guarantee — see pricing.
The Mistakes That Cost People Months
- Applying for an ITIN when eligible for an SSN. The IRS rejects W-7s from SSN-eligible applicants. Check SSN eligibility first.
- Using an EIN for personal filings or an ITIN for the business. Each number stays in its lane: entity filings under the EIN, personal filings under the ITIN.
- Letting an ITIN expire before tax season. Three consecutive unused years and it lapses on December 31 — renew before filing, not after.
- Waiting on an ITIN before requesting an EIN. Unnecessary — non-residents can get an EIN with "FOREIGN" on SS-4 line 7b, no ITIN required.
- Assuming any of these numbers changes immigration or work status. They don't. Tax IDs and immigration status are separate systems run by separate agencies.
Bottom Line
Match the number to what it identifies. A business entity gets an EIN — free, instant online with an SSN/ITIN, permanent. An individual authorized to work gets an SSN from the SSA. An individual with U.S. tax obligations and no SSN eligibility gets an ITIN — for tax administration only, nothing else. Most non-resident founders end up with an EIN for the company and an ITIN for themselves, and getting both right the first time is what keeps tax season uneventful.
Frequently Asked Questions
What is the difference between an EIN, ITIN, and SSN?
An EIN identifies a business entity to the IRS. An SSN identifies an individual authorized to work in the U.S. and is issued by the Social Security Administration. An ITIN identifies an individual with U.S. tax obligations who is not eligible for an SSN. All three are 9-digit numbers, but they are not interchangeable.
Can I have both an ITIN and an EIN?
Yes, and many non-resident business owners need both. The EIN belongs to the business entity, while the ITIN belongs to you as an individual for your personal U.S. tax filings.
Does an ITIN authorize you to work in the U.S.?
No. An ITIN does NOT authorize you to work in the United States. It is for U.S. tax administration only and does not confer or change immigration status or entitle the holder to Social Security benefits.
Which tax ID do I need to open a U.S. business bank account?
An EIN. Banks require the business entity's EIN plus formation documents and the owner's identification, such as a passport. See open a US bank account as a non-resident.
Do I need an SSN to get an EIN?
No. An SSN or ITIN lets you use the instant online application, but non-U.S. residents without either can get an EIN by phone, fax, or mail using Form SS-4 with "FOREIGN" written on line 7b.
What happens to my ITIN if I later get an SSN?
You stop using the ITIN, use the SSN from that point on, and notify the IRS in writing so your tax records are combined under the SSN. The ITIN is retired; you should never use both numbers.
Which tax IDs expire?
Only the ITIN. It expires if not used on a federal tax return for 3 consecutive tax years, lapsing on December 31 of that third year. EINs and SSNs never expire.
Do any of these tax IDs cost money?
No. The IRS issues EINs and ITINs for free, and the Social Security Administration issues SSNs for free. Fees apply only when you hire a preparer or Certified Acceptance Agent to handle the application for you.
Does a foreign Amazon seller need an EIN or an ITIN?
Usually an EIN for the entity that sells on Amazon, collected during the platform's tax interview. The owner may also need an ITIN if personal U.S. filing obligations exist, such as treaty claims or income reported on Form 1040-NR.
