Business Formation · 2026-04-13

What Is an ITIN? SSN vs ITIN vs EIN — Which One Do You Need?

Three numbers, three different purposes. SSN is for US residents with work authorization. ITIN is for individuals who need to file US taxes but cannot get an SSN. EIN is for companies. Most non-resident LLC owners only need an EIN — but certain situations require an ITIN too. Here is how to decide.

Three Numbers, Three Different Systems

If you are forming a US LLC as a non-resident, you will encounter three acronyms: SSN, ITIN, and EIN. They look similar — all issued by the IRS or Social Security Administration, all formatted as multi-digit numbers — but they serve completely different purposes and are issued to completely different groups of people.

Getting them confused causes real problems. Entering an ITIN where a form asks for an SSN can trigger fraud flags. Applying for an ITIN when you only need an EIN wastes months. Using your personal ITIN as your company's tax ID creates a compliance mess that is difficult to untangle later.

Here is the clear breakdown.

SSN — Social Security Number

Who gets it: US citizens and permanent residents, plus non-citizens authorized to work in the US (e.g., H-1B, L-1, OPT visa holders).

What it is for: Personal tax identification, employment eligibility, social security benefits tracking, credit history.

Format: XXX-XX-XXXX (example: 123-45-6789)

How to get it: Apply at a Social Security Administration (SSA) office with proof of identity, age, and work authorization. Processing takes 2-4 weeks.

Key point for non-residents: You cannot get an SSN unless you have US immigration status that authorizes employment. Being an LLC owner does not qualify you for an SSN. Forming a Wyoming LLC does not give you work authorization in the United States.

ITIN — Individual Taxpayer Identification Number

Who gets it: Individuals who need to file US tax returns or be reported on US tax documents, but who are not eligible for an SSN. This includes non-resident aliens with US tax filing obligations, dependents or spouses of US citizens/residents, and non-residents claiming tax treaty benefits.

What it is for: Personal US tax filing only. It is not proof of work authorization, immigration status, or eligibility for social security benefits.

Format: 9XX-XX-XXXX (always starts with 9, with digits 70-88, 90-92, or 94-99 in the fourth and fifth positions)

How to get it: Submit IRS Form W-7 along with a completed federal tax return (or documentation of a tax treaty benefit claim). You must also provide original identification documents (passport) or certified copies from the issuing agency. Processing takes 7-14 weeks.

Application methods:

**By mail** — Send W-7, tax return, and original documents to the IRS ITIN Operation Center in Austin, TX. Your passport will be mailed back after processing. This is the slowest option and requires surrendering your passport for weeks.

**Through a Certifying Acceptance Agent (CAA)** — A CAA is an IRS-authorized individual or organization that can verify your documents in person and send certified copies to the IRS. You keep your original passport. This is the recommended method for most non-residents.

**In person at an IRS Taxpayer Assistance Center** — Available at select IRS offices. Limited locations and availability.

Renewal: ITINs expire if not used on a federal tax return for three consecutive years, or if issued before 2013 (on a rolling schedule). Renewal uses the same W-7 form.

EIN — Employer Identification Number

Who gets it: Any business entity — LLC, corporation, partnership, trust, estate. Single-member LLCs owned by non-residents are required to have one.

What it is for: Company tax identification, opening business bank accounts, filing business tax returns, hiring employees, setting up payment processing (Stripe, PayPal, etc.).

Format: XX-XXXXXXX (example: 84-1234567)

How to get it: Apply using IRS Form SS-4. If you have an SSN or ITIN, you can apply online and receive the EIN immediately. Without an SSN or ITIN, you must apply by fax (4-7 business days) or mail (4-6 weeks). A third-party designee with an SSN or ITIN can apply on your behalf online.

Key point: The EIN belongs to the company, not to you personally. Your LLC's EIN and your personal SSN or ITIN are separate identifiers in separate systems.

For a deeper dive on the EIN application process and address requirements, read EIN Application Address Requirements for Non-Residents.

Side-by-Side Comparison

| | SSN | ITIN | EIN |

|---|---|---|---|

| Issued by | Social Security Administration | IRS | IRS |

The Decision Tree: Which Numbers Do You Actually Need?

Scenario 1: You are forming a new LLC and have no US-source personal income

You need: EIN only.

If you are a non-resident forming a Wyoming LLC, and the LLC is the entity earning income (not you personally), you need an EIN for the LLC. You do not need an ITIN just to own an LLC.

The LLC files its own information returns. As a single-member LLC with a foreign owner, the LLC files Form 5472 and a pro-forma 1120 using the LLC's EIN. Your personal tax number is not required on these forms if you have no US personal tax filing obligation.

Scenario 2: You need to claim tax treaty benefits

You need: EIN + ITIN.

If your country has a tax treaty with the US and you want to claim reduced withholding rates on US-source income (dividends, royalties, service fees), you need an ITIN. The treaty benefit claim is made on your personal tax return or on Form W-8BEN, which requires your personal tax identification number.

Scenario 3: You have US-source personal income

You need: EIN + ITIN.

If you receive income that is reported to you personally — not through the LLC — such as rental income, speaking fees, or consulting income paid directly to you as an individual, you need to file a US personal tax return. That requires an ITIN.

Scenario 4: Your bank asked for an SSN but you are a non-resident

You probably need to provide: EIN (for the LLC account) or ITIN (for personal accounts).

This is the most common confusion. A bank form asks for "SSN/TIN" and you do not have an SSN. Here is the translation:

**If you are opening a business bank account for your LLC:** Provide the LLC's EIN. The account belongs to the LLC, not to you. The "responsible individual" section may ask for your personal tax ID — provide your ITIN if you have one, or explain that you are a non-resident individual without US tax filing obligations and do not have an SSN or ITIN.

**If you are opening a personal account:** You will need an ITIN. Most US banks require an SSN or ITIN for personal accounts. Some banks (particularly those serving international clients) will accept a passport number for non-resident accounts, but this is not universal.

For the full guide on opening a US bank account as a non-resident LLC owner, see US Bank Account for Wyoming LLC: Complete Guide 2026.

Common Mistakes to Avoid

Using your ITIN as your LLC's tax ID. Your ITIN is personal. Your LLC's EIN is separate. Do not put your ITIN on business forms that ask for the company's tax ID, and do not put the EIN on personal forms that ask for your individual tax ID.

Applying for an ITIN before you need one. The IRS rejects W-7 applications that are not accompanied by a valid reason — typically a tax return being filed or a tax treaty benefit being claimed. You cannot get an ITIN "just in case." Wait until you have a specific filing obligation.

Assuming an EIN lets you skip the ITIN. If you personally owe US taxes or need to claim treaty benefits, the EIN does not substitute for an ITIN. They identify different entities (your company vs. you personally).

Delaying the EIN because you think you need an ITIN first. You do not need an ITIN to get an EIN. You can apply for an EIN by fax or mail without any personal tax ID. Many formation services and registered agents can file the SS-4 on your behalf as a third-party designee.

The ITIN Application Process in Brief

If you determine that you do need an ITIN, here is the process:

1. Prepare your federal tax return (or gather documentation for a tax treaty benefit exception).

2. Complete IRS Form W-7 — the ITIN application.

3. Gather identification documents — a valid passport is the single document that satisfies both identity and foreign status requirements.

4. Choose your submission method — CAA (recommended), mail, or in-person.

5. Submit and wait — 7-14 weeks processing time. The IRS will mail your ITIN assignment letter to the address on the W-7.

Using a Certifying Acceptance Agent is strongly recommended. A CAA can verify your passport in person, so you do not need to mail the original to the IRS. The IRS maintains a list of CAAs on their website, including agents located outside the US.

Summary: The Minimum You Need

For most non-resident LLC owners, the answer is simpler than it appears:

**EIN** — required for every LLC. Apply as soon as your LLC is formed. Use your [commercial sublease address](/blog/ein-application-address-requirements-non-resident) on the SS-4 for document consistency.

**ITIN** — required only if you have a personal US tax filing obligation or need to claim treaty benefits. Do not apply until you have a concrete reason.

**SSN** — not available to you unless you have US work authorization. Do not attempt to apply for one.

When a bank, platform, or government form asks for your "SSN/TIN," it is usually asking for whichever taxpayer identification number applies to the entity in question — EIN for the LLC, ITIN or SSN for you personally. Knowing which number goes where prevents the mismatches that trigger verification delays.