Tax ID Numbers for Ecommerce Sellers: EIN, ITIN, SSN Explained

Here's the answer most sellers are looking for: a US sole proprietor can legally sell using just their SSN, an LLC or corporation should get an EIN (free, from the IRS, in minutes if you have an SSN), and an international seller can get an EIN with no SSN and no ITIN through a fax-and-phone process that costs nothing but patience. The ITIN, which people constantly confuse with a business tax ID, is a personal number most sellers never need. Now the details, because the details are where marketplaces suspend accounts and the IRS sends letters.

The three numbers, in one table

Number	What it is	Who it identifies	How you get it
SSN	Social Security number	A US citizen or authorized resident, personally	Social Security Administration
EIN	Employer Identification Number	A business entity (or a sole prop who requests one)	IRS, free, Form SS-4 or online
ITIN	Individual Taxpayer Identification Number	A person who must file US taxes but can't get an SSN	IRS, Form W-7 with identity documents

All three are TINs (taxpayer identification numbers), which is the umbrella term tax forms use. When Amazon's tax interview asks for your TIN, it's asking for whichever of these applies to you, and matching the right number to the right situation is the entire game.

Which one your business actually needs

US sole proprietor, no employees: your SSN is legally sufficient. Get an EIN anyway. It's free, takes ten minutes, and means your SSN stops appearing on every W-9 you hand a supplier, wholesale customer or platform. Identity theft aside, an EIN is required the moment you hire an employee, and having one already makes wholesale applications and business banking smoother.

Single-member LLC (US owner): the IRS treats it as a disregarded entity, so taxes flow to your personal return either way. But banks require an EIN to open the business account that keeps your liability protection meaningful, and payroll requires one. In practice, every LLC should have its own EIN from day one.

Multi-member LLC, partnership, S-corp or C-corp: an EIN is mandatory, full stop. These entities file their own returns and can't do it on anyone's SSN.

Foreign-owned single-member LLC: an EIN is mandatory even with zero employees and zero US tax owed, because the LLC must file Form 5472 annually, and the 5472 requires an EIN. Missing that filing costs $25,000 per year; our Form 5472 guide covers the whole obligation. If you formed a Wyoming or Delaware LLC from abroad and nobody mentioned the 5472, put this paragraph at the top of your list.

Getting an EIN with an SSN: ten minutes, zero dollars

The IRS online EIN application (weekdays, roughly 7am to 10pm Eastern) issues the number instantly. You'll name a responsible party, the human who controls the entity, and that person's SSN or ITIN goes on the application. Two rules trip people: the responsible party must be an individual, not another company, and the IRS issues only one EIN per responsible party per day, which matters if you're spinning up multiple LLCs.

And it is free. The formation mills charging $75 to $300 for "EIN filing service" are charging you to type your own answers into a free government form. The only people with a legitimate reason to pay for help are foreign owners navigating the no-SSN route, and even that is doable solo.

Getting an EIN without an SSN: the international route

No SSN, no ITIN, no US address: you can still get an EIN, directly from the IRS. The online tool won't work for you (it demands an SSN or ITIN), so the path is Form SS-4 by fax or phone:

• Fill out Form SS-4 for the entity. On line 7b, where it asks for the responsible party's SSN or ITIN, write "Foreign". That's the officially sanctioned move, not a trick.
• Fax it to the IRS's international EIN unit (the current fax number is on the SS-4 instructions). Faxed applications with a return fax number typically come back in roughly a week or two; mail takes a month or more.
• Or phone it in: international applicants can call the IRS international EIN line (also listed in the SS-4 instructions; it's a Pennsylvania number, +1 267 941 1099, not toll-free) and receive the EIN during the call. Have the completed SS-4 in front of you; the agent walks through it line by line. Budget for hold time and US business hours.

Total cost: a fax and a phone call. The "EIN for foreigners, $250" services are filling out this same form; some are competent, some file wrong entity types, and none are necessary. Once the EIN exists, it unlocks the rest of the stack: the marketplace tax interview, a US business bank account, and state registrations like Florida's paper DR-1 or Washington's business license, both of which accept an EIN in place of an SSN. Setting up this whole sequence for non-US sellers is the daily work of our international sellers practice.

The ITIN: probably not needed, occasionally essential

The ITIN gets oversold to international sellers as a must-have. It isn't. You do not need an ITIN to get an EIN, form an LLC, open many business bank accounts, or pass a marketplace tax interview as a foreign person (that's a W-8BEN, no US TIN required in most treaty situations, though providing your home-country TIN gets you treaty rates).

When you genuinely need one: you personally must file a US return, most commonly a 1040-NR because your LLC's activity created US-taxable income, or you're claiming treaty benefits that require a US TIN on a withholding form. Then it's Form W-7, filed with a return, with certified identity documents, and six to ten weeks of waiting. The order matters: EIN first (fast, unlocks business operations), ITIN later if and only if a filing requires it. A good advisor decides the "if"; whether a foreign seller's marketplace income is US-taxable at all is a real analysis, not a checkbox, and it's covered in our Amazon seller taxes guide.

Marketplace tax interviews: where the wrong number gets expensive

Every platform (Amazon, Walmart, eBay, Etsy, TikTok Shop, PayPal, Stripe) makes you complete a tax interview so they can file information returns. US persons complete a W-9; foreign persons a W-8BEN or W-8BEN-E. Three failure modes we see constantly:

• Name/TIN mismatch. The platform runs your name and TIN against IRS records. A single-member LLC that enters the LLC's name with the owner's SSN (or the owner's name with the LLC's EIN) fails matching. The rule for a disregarded LLC on a W-9: the owner's name on line 1, the LLC name on line 2, and either the owner's SSN or the LLC's EIN works, but the name on line 1 has to match whichever number you give. Fail matching twice and platforms start 24% backup withholding or freeze payouts.
• Foreign owner completing a W-9. A foreign person who forms a US LLC is still a foreign person; a single-member US LLC with a foreign owner generally certifies foreign status (W-8BEN through to the owner), not a W-9. Getting this wrong misstates your status to the IRS, in writing.
• Stale interviews after restructuring. Sole prop in 2023, LLC in 2024, S-corp election in 2026, and the marketplace still reports under your SSN. Now your 1099-K lands on the wrong taxpayer and your returns don't reconcile. Redo the tax interview the same week the entity changes.

One number serves every platform, by the way. Sellers sometimes ask whether Walmart or TikTok Shop needs "its own" EIN: no. One entity, one EIN, entered identically in every tax interview. What multiplies is the interviews themselves, and keeping them consistent is the point; five platforms reporting the same TIN with the same name is what makes your annual tax filing reconcile in one pass instead of five.

Sole prop vs LLC: what changes for your tax IDs

Forming an LLC doesn't change your income tax (a single-member LLC is disregarded; profit still lands on your Schedule C), but it does reshuffle your identifiers. The LLC gets its own EIN. The bank account moves to the LLC's name and EIN. The marketplace tax interview gets redone. Your suppliers get new W-9s. And if you later elect S-corp status, the LLC needs its own EIN regardless of what you used before, because it's now filing its own return, plus payroll accounts, because you're now an employee of your own company.

Two more transitions with EIN consequences: a sole prop who incorporates needs a new EIN (the corporation is a new taxpayer), and a single-member LLC that adds a member becomes a partnership, also a new-EIN event. The EIN follows the taxpayer, not the brand name.

Don't confuse federal IDs with state ones

The EIN is federal. States issue their own registrations on top: sales tax permits (like Florida's and Washington's), state withholding accounts once you run payroll, and state entity registrations. "I have an EIN" and "I'm registered to collect sales tax in the states where I have nexus" are entirely different sentences, and sellers regularly have the first while assuming it covers the second. It doesn't; state registration is its own project, and it's part of what our ecommerce tax services handle.

The order of operations for a new seller

Sequencing saves weeks. For a US founder: form the LLC, get the EIN online the same day (the LLC must exist first; the application asks for its legal name and formation state), open the bank account with the formation documents and EIN letter, then complete the marketplace tax interview with the new entity before the first sale settles. Done in that order, it's a one-week project and every 1099-K ever issued lands on the right taxpayer.

For an international founder the same chain runs longer, so start earlier: LLC formation (a few days), EIN by fax or phone (one to three weeks), bank or fintech account (days to weeks, and the EIN letter is the gating document), then the tax interview, then state registrations as nexus develops. Two months of calendar time is a realistic budget, and the EIN sits on the critical path for everything. The classic mistake is launching on a personal account "temporarily" while the paperwork catches up; six months later the books hold a tangle of personal and business activity that costs real money to unpick, and the platform is still reporting under the wrong identity.

Keeping the EIN's paperwork straight afterward

The IRS mails a CP 575 confirmation letter when it issues your EIN. Scan it and keep it forever; banks, wholesale suppliers and platforms ask for it, and the IRS never reissues it. Lose it and the replacement is a 147C verification letter, requested by phone, which takes a call and patience but works. Two ongoing duties come with the number: if your responsible party changes (a partner buys you out, ownership transfers), Form 8822-B is due within 60 days, and if the business address changes, the same form updates it. Neither is hard; both are the kind of thing that surfaces as a problem years later when IRS mail goes to an apartment you left in 2024.

What doesn't require a new EIN, despite persistent internet folklore: moving states, changing your DBA or brand name, adding a new sales channel, or switching banks. The EIN tracks the taxpayer. As long as the entity and its tax classification are the same, the number rides along.

Tax ID FAQ for sellers

How long does it take to get an EIN? Minutes online with an SSN or ITIN. Without one: same-day by phone if you get through, a week or two by fax, a month-plus by mail.

Does an EIN cost anything? No. The IRS charges nothing, ever. Anyone charging you is charging for typing.

Can I sell on Amazon without an SSN? Yes. Foreign sellers complete the tax interview with a W-8BEN, no US TIN required in most cases, and a US LLC owned by a foreign person runs on an EIN obtained without any SSN.

Is an EIN the same as a business license or a sales tax permit? No on both. The EIN is federal identification; licenses and sales tax permits are state and local registrations you obtain separately, where your operations require them.

Do I need an ITIN to open a US bank account? Usually not for a business account: banks and fintechs generally want the LLC's formation documents, the EIN letter and your passport. Requirements vary by institution, which is why this step is worth asking about before you pick a bank.

The 15-minute checkup

Pull up three things: your marketplace tax interview, your bank account title, and last year's 1099-Ks. All three should show the same name and the same TIN, and that pair should match your current entity. If they don't agree, you've found this year's cleanup project, and it's dramatically cheaper to fix before the IRS's matching computers or a platform's compliance team find it first. Whether you're a US reseller who leveled up from hobby to business or an international founder with a Delaware LLC and a compliance stack you inherited from a YouTube video, we'll look at the whole picture in a free Ecommerce Books Teardown; request one here.