Short answer: Yes, in almost every US state you need a federal Employer Identification Number (EIN) to complete sales tax registration. A small number of states will let a sole proprietor register using their Social Security Number (SSN) instead, but for any LLC, corporation, partnership, or non-US founder, the EIN is non-negotiable. Foreign sellers without an SSN can still obtain an EIN — they just have to apply by fax or international phone using Form SS-4, which typically takes 1–2 weeks rather than the instant turnaround US residents get online.
If you’d rather not figure out the EIN application, the state portals, or the nexus analysis behind any of this, Sales Tax Compliance USA handles the whole thing end-to-end — EIN acquisition, nexus study, multi-state registration, and ongoing filing — for a single fee.
Short Answer: Yes in Most States, But Not Always
Here’s the real-world breakdown for 2026:
- Entity sellers (LLCs, corporations, partnerships, foreign companies): You need an EIN. Every state. No exceptions.
- US sole proprietors: A handful of states will accept your SSN at the registration screen. Most will still ask for or strongly prefer an EIN.
- Foreign sole proprietors with no SSN/ITIN: You need an EIN. There is no SSN workaround. The IRS issues EINs to foreign individuals via Form SS-4 (fax/phone), and you do not need a US entity to get one.
The “do I need an EIN” question gets confusing because three separate topics get conflated:
- The federal tax ID (EIN, SSN, or ITIN) — what the IRS issues you.
- The state sales tax permit number — what the state Department of Revenue issues you after you register.
- Business licenses — separate city/county permits unrelated to sales tax.
This article is about #1 and how it gates your access to #2.
Done-for-you note: If you’re a non-US founder reading this, the fastest practical path is to let us obtain the EIN by fax as part of a registration package — typical turnaround 1–2 weeks. Trying to navigate the IRS international line yourself often costs more time than it saves.
What Is an EIN and Why Do States Ask for It?
An EIN (Employer Identification Number) is a 9-digit federal tax identifier issued by the IRS in the format XX-XXXXXXX. It identifies a business entity (or, for a sole prop, an individual operating a business) for federal tax purposes. The IRS issues EINs free of charge — anyone telling you it costs money is selling you a service, not the EIN itself.
EIN vs. SSN vs. ITIN vs. State Tax ID — Don’t Confuse Them
These four IDs do different things and are not interchangeable:
| ID | Issued By | Who Gets It | Used For Sales Tax Registration? |
|---|---|---|---|
| SSN (Social Security Number) | Social Security Administration | US citizens, permanent residents, work-authorized non-residents | Sometimes — sole proprietors only, in select states |
| ITIN (Individual Taxpayer Identification Number) | IRS | Non-residents who need to file US individual tax returns but are not work-authorized | Generally not accepted as a business tax ID for sales tax registration |
| EIN (Employer Identification Number) | IRS | Any business entity, plus foreign individuals who need a US business tax ID | Yes — universally accepted |
| State Tax ID / Sales Tax Permit Number | State Department of Revenue | Anyone registered to collect sales tax in that state | This is what you receive AFTER registering — not what you provide |
The most common mistake foreign sellers make: assuming an ITIN will let them register a business for sales tax. It won’t. ITINs are individual income-tax IDs, not business IDs. State sales tax portals expect either an SSN (for a US sole prop) or an EIN (for everything else).
Why State DORs Require a Federal Identifier
State Departments of Revenue use your federal tax ID to:
- Cross-match against IRS data to verify the business actually exists and to flag identity fraud.
- Issue you a separate state-level sales tax permit number that gets attached to your filings.
- Enable interstate information-sharing under reciprocal agreements between state DORs and the IRS.
- Pursue collection if you under-report — your EIN is the thread that connects state liability back to a federally identifiable taxpayer.
A common misconception: “the EIN IS my sales tax permit.” It’s not. The EIN is the prerequisite. Each state issues its own separate sales tax permit number (often called a “Certificate of Authority” in New York sales tax registration involves state-specific procedures that depend on your business structure and activities. If you need to register in New York, contact us for a current review., a “Seller’s Permit” in California sales tax registration with the CDTFA has its own mechanics that vary by entity type and operations. If you need to register in California, contact us for a current review., etc.) once you register.
State-by-State: Where an EIN Is Required to Register for Sales Tax
The matrix below reflects what state DOR online registration portals actually ask for in 2026. We’ve grouped states into four categories.
States That Require an EIN for Entities (No Exceptions)
For LLCs, corporations, and partnerships, every sales-tax state requires an EIN. There is no state in the US that will register an entity for sales tax based on the entity’s state-of-formation number alone. This includes:
- California — CDTFA Seller’s Permit registration requires FEIN for entities
- New York’s Certificate of Authority application (Form DTF-17) only requires an EIN if the business is not a sole proprietorship or plans to hire employees; otherwise the field can be left blank and a temporary NY ID is assigned (see DTF-17 instructions).
- Texas, Florida, Washington, Illinois, Pennsylvania, and every other sales-tax state.
States That Accept SSN for Sole Proprietors
If you’re a US sole proprietor (no LLC, no corporation), several states will let you register using your SSN. The portals typically have a radio button asking whether you’re an individual or an entity, and the entity branch demands an EIN while the individual branch will accept an SSN.
The catch: many sole proprietors who choose this route later regret it (see “Sole Proprietors: SSN or EIN” below).
Important caveat for foreign sole proprietors: These SSN-acceptance options are useless to you. If you don’t have an SSN, you go straight to the EIN path.
States With a State-Issued Pre-Step
A few states require their own state-level business identifier before you can register for sales tax:
- Washington issues a Unified Business Identifier (UBI) through the Business Licensing Service. You’ll provide your EIN during the UBI application; the UBI is then your master state-level ID.
- Several other states have similar “register your business with the state first” pre-steps that fold sales tax registration into a broader business-license registration.
States With No Statewide Sales Tax (Mostly No Registration Needed)
The “NOMAD” states have no statewide sales tax:
- New Hampshire
- Oregon
- Montana
- Alaska — but local jurisdictions in Alaska impose sales tax, administered through the Alaska Remote Seller Sales Tax Commission (ARSSTC). Remote sellers exceeding the ARSSTC threshold must register with ARSSTC, and the ARSSTC application asks for an EIN.
- Delaware
If your only US activity is in NOMAD states (excluding Alaska local), you have no state sales tax registration obligation at all — and the EIN question is moot for sales tax purposes (though you may still need an EIN for federal income tax, banking, or marketplace-platform reasons).
Summary Matrix
| Seller Type | EIN Required? | Workaround? |
|---|---|---|
| US LLC / Corporation / Partnership | Yes | None |
| US sole proprietor | Often, but several states accept SSN | Use SSN where allowed |
| Foreign company (Ltd, GmbH, Pty Ltd, etc.) | Yes | None — apply via Form SS-4 by fax |
| Foreign individual / sole proprietor | Yes | None — apply via Form SS-4 by fax (no US entity needed) |
| Marketplace-only seller (no other nexus) | Often no registration needed at all | See marketplace facilitator section |
Foreign Sellers: How to Get an EIN With No SSN and No US Entity
This is the section foreign sellers come here for. The IRS does issue EINs to non-US persons. The path is just slower and clunkier than for US residents.
Why You Cannot Use the Online EIN Application
The IRS online EIN tool requires the “responsible party” to have an SSN, ITIN, or existing EIN. If you’re a foreign founder with none of those, the online tool will reject you. This is by design — it’s not a bug or a workaround you can find.
Form SS-4 by Fax — The Standard Path (1–2 Weeks)
The standard route for foreign applicants:
- Complete Form SS-4 (Application for Employer Identification Number).
- Fax it to the IRS international fax number.
- Wait for the EIN to be faxed back, typically within 1–2 weeks if the form is correct.
If your form has errors, IRS rejects it and you start over — adding weeks to the timeline.
Form SS-4 by International Phone — Fastest Path
Foreign applicants can also call the IRS international EIN line. If the agent accepts your servicelication over the phone, you’ll receive the EIN immediately on the call. This is the fastest path when it works.
Reality check: the international EIN line has long hold times, narrow operating hours (US Eastern time), and the agent may still refer you to fax submission if anything is unclear about the form. Have all SS-4 fields prepared before calling.
What to Put on Line 7b When You Have No SSN/ITIN
This is where most foreign DIY applications go wrong. Form SS-4 Line 7a asks for the responsible party’s name; Line 7b asks for their SSN, ITIN, or EIN. If the responsible party has none of those (a typical foreign individual), the accepted convention is to write “Foreign” in Line 7b. The IRS instructions explicitly contemplate this case for international applicants.
If you incorrectly leave Line 7b blank, the IRS often rejects the application.
“Reason for Applying” — Pick the Right Box
The most common acceptable reasons for foreign applicants:
- “Started new business” — if you’re forming a US LLC.
- “Compliance with IRS withholding regulations” — if you have no US entity but need an EIN for US tax compliance (e.g., to collect sales tax).
- “Banking purposes” — if you’re opening a US business bank account.
Foreign individuals registering for US sales tax usually fit “Compliance with IRS withholding regulations” — even though sales tax isn’t withholding tax, this is the IRS-accepted catch-all for foreign persons needing a US tax ID for compliance reasons.
You Do NOT Need a US LLC to Get an EIN
This is one of the most expensive misconceptions in the foreign-seller market. You’ll see Twitter threads and YouTube videos telling you to form a Wyoming or Delaware LLC “to get an EIN.” A foreign individual can obtain an EIN directly without forming any US entity. Forming an unnecessary LLC adds a registered-agent fee, an annual report fee, state franchise tax, and (in some states) a US tax filing obligation — all to solve a problem you didn’t have.
There are legitimate reasons to form a US LLC (liability protection, banking, marketplace requirements, perception). Getting an EIN is not one of them.
Common SS-4 Rejection Reasons for Non-US Applicants
In our work submitting EIN applications for foreign clients, the most frequent rejections come from:
- Line 7b left blank instead of “Foreign”
- Mismatch between entity type and “Reason for applying”
- Foreign address fields formatted incorrectly
- Responsible party name not matching passport/ID
- Calling the wrong “Type of entity” box (e.g., calling yourself a “corporation” when you’re actually a foreign sole proprietor)
Done-for-you alternative: Sales Tax Compliance USA obtains EINs for non-US founders as part of every multi-state registration package. We’ve submitted hundreds of SS-4s by fax — typical turnaround is 1–2 weeks, and we handle the rejection-and-resubmit cycle so you don’t have to.
Sole Proprietors: SSN or EIN — Which Should You Use?
If you’re a US sole proprietor with both options on the table, here’s the framework.
When SSN Is Fine
- You’ll never incorporate.
- You don’t sell wholesale (so you’ll never hand a resale certificate to a supplier with your SSN on it).
- You only need to register in 1–2 states and want to move fast.
When You Should Get an EIN Anyway
- You plan to incorporate within 12 months. Getting the EIN now and registering under it means you don’t have to re-register everything later. Re-registration in some states isn’t a quick edit — it can require closing the SSN-based account and opening a new EIN-based account, with potential filing-frequency reassignment, surety-bond re-posting, and a compliance gap window.
- You issue resale certificates to suppliers. Your resale certificate carries your registered tax ID. With an SSN, you’re handing your Social Security Number to wholesalers — an identity-theft risk you don’t need.
- Marketplaces ask for it. Amazon, Walmart, eBay, and most major marketplaces ask for an EIN during onboarding regardless of state sales tax registration requirements.
- You plan to open a business bank account. Most US banks require an EIN for a business account, even for a sole prop.
The Hidden Cost of Registering With SSN, Then Switching
The most painful version of this story:
A US sole prop registers in 8 states using their SSN. Eighteen months later, they form an LLC for liability protection and want their sales tax accounts under the LLC’s EIN. In some states, “updating” the tax ID is straightforward. In others, it’s effectively closing the old account (with a final return) and opening a new one (with re-posted security deposits and a new permit number). The transition window can create filing gaps, missed returns, and penalty exposure.
If incorporation is on your horizon, getting the EIN at the start saves significant compliance pain later.
What If You Need to Register Now and the EIN Hasn’t Arrived?
Here’s the timing trap. You’ve crossed economic nexus in five states this month. State DORs expect prompt registration. Your SS-4 is sitting in the IRS fax queue and you won’t see your EIN for 1–2 weeks. What now?
States That Will Issue a Permit Pending EIN
Some state portals allow you to enter “EIN pending” or attach a written explanation, with a follow-up to provide the EIN once received. Practice varies by state and can change, so we don’t publish a definitive list — we contact the DOR directly when this comes up.
States That Will Reject the Application
Other states’ portals are hard-coded: no EIN, no submission. You wait.
Marketplace-Only Sellers: You May Not Need to Register at All
This is the most under-discussed angle in the entire EIN-for-sales-tax conversation.
Every sales-tax state has now passed a marketplace facilitator (MF) law shifting the collection-and-remittance obligation from the third-party seller to the marketplace itself (Amazon, Walmart, eBay, Etsy, etc.). If 100% of your US sales go through marketplaces, the marketplace is collecting and remitting the tax for you in every state that matters.
This means in many states, marketplace-only sellers with no other physical or economic nexus have zero sales tax registration obligation — making the EIN question moot for those states.
The exceptions to watch for:
- States where you have FBA inventory. Storing physical inventory in a state generally creates physical-presence nexus. California, for example, requires marketplace sellers to register for a Seller’s Permit if they have FBA inventory in California, even when 100% of their sales are facilitated by Amazon.
- States that require marketplace sellers to register regardless. Marketplace sellers in New York whose sales are entirely facilitated by a marketplace provider and who receive the provider’s Certificate of Collection are NOT required to obtain their own Certificate of Authority—the marketplace provider collects and remits the tax (see NY DTF marketplace guidance)..
- Use-tax reporting thresholds in some states.
- Sales outside the marketplace — even one direct-to-consumer Shopify sale into a state where you have economic nexus can trigger registration.
Don’t apply for an EIN, then register in 20 states, until you’ve done a nexus study. Many sellers we onboard expected to register in 15+ states and end up registering in 3–5 because the marketplace is handling the rest. That’s thousands of dollars per year in avoided filing fees and compliance overhead.
Our nexus review tells you exactly which states you legally must register in — before you waste time on EINs and applications you don’t need.
Step-by-Step: Getting Your EIN and Registering for Sales Tax
If you’re determined to do this yourself, here’s the correct order of operations.
Step 1: Determine Where You Have Nexus
Before applying for anything, identify where you legally have a sales tax obligation:
- Physical nexus: offices, employees, inventory (including FBA), trade shows, contractors.
- Economic nexus: sales-dollar and/or transaction-count thresholds in each state — varies by state, typically $100K or $250K, with a few outliers like California’s $500,000 economic nexus threshold and New York’s economic nexus test for remote sellers uses a conjunctive sales-and-transactions standard, but the exact thresholds and how they apply turn on current DTF guidance and your specific sales profile. If you may be approaching New York economic nexus, contact us for a current review..
- Marketplace facilitator considerations: which sales the marketplace is already handling.
Step 2: Obtain Your EIN (US or Foreign Path)
- US founder with SSN: Apply via the IRS online EIN application — instant issuance.
- Foreign founder, no SSN/ITIN: Form SS-4 by fax (1–2 weeks) or international phone (same-day if you get through).
- Sole prop using SSN: Skip this step if your nexus states accept SSN and you have no plan to incorporate.
Step 3: Register in Each Nexus State
Go to each state DOR’s online registration portal. Provide:
- Your EIN (or SSN where allowed)
- Entity details, owners/responsible parties
- Projected monthly sales
- Products sold (NAICS code or state-specific category)
- Effective date of nexus
Each state issues you a sales tax permit number, an initial filing frequency assignment, and a first-return due date.
Step 4: Set Up Filing Calendars and Begin Collection
- Configure your e-commerce platform / marketplace to collect tax from the effective date forward.
- Track due dates per state (filing frequencies vary — monthly, quarterly, annual).
- File even when you have zero sales (“zero returns” are mandatory in nearly every state once registered).
Common mistake: registering “just in case” in states where you don’t actually have nexus. Once registered, you have a perpetual filing obligation — even with zero sales — until you formally close the account. Over-registration creates years of unnecessary compliance cost.
Or, Skip All of This — Have STCU Handle It
This is what we do every day for cross-border e-commerce founders, Amazon FBA sellers, and overwhelmed US founders who don’t want to learn another set of state portals:
- EIN acquisition for non-US founders — Form SS-4 by fax, typical 1–2 week turnaround. We handle Line 7b correctly the first time.
- Nexus study — we tell you exactly where you have to register, so you don’t pay to register in states where the marketplace is already handling everything.
- Multi-state registration — we apply in every required state under one engagement.
- Ongoing filing and remittance — you never log into a state DOR portal again.
- One flat fee. No software for you to learn, no per-transaction pricing, no surprise charges.
We’re not a tax software platform. We’re a done-for-you US sales tax compliance service — built for founders who’d rather have someone handle the whole stack.
Frequently Asked Questions
Can I register for sales tax without an EIN?
In most US states, no — entities require an EIN. A few states accept an SSN for US sole proprietors. Foreign sellers without SSN/ITIN must obtain an EIN before registering.
Do I need an EIN if I’m a sole proprietor?
Not always for sales tax registration — several states accept your SSN. But if you plan to incorporate within a year, issue resale certificates to wholesalers, or sell on marketplaces that require an EIN, get one anyway.
Can a foreign seller get an EIN without an SSN or ITIN?
Yes. File Form SS-4 by fax or international phone with the IRS. Write “Foreign” on Line 7b for the responsible party’s tax ID. You don’t need a US LLC.
How long does it take to get an EIN as a non-US applicant?
By fax, typically 1–2 weeks if the form is filled out correctly. By international phone, often immediate when you get through. The IRS online tool is not available to applicants without an SSN/ITIN.
Do I need a US LLC to register for sales tax?
No. A foreign individual or foreign company can obtain an EIN and register for state sales tax without forming a US entity. Forming an unnecessary US LLC adds annual fees and federal compliance obligations.
Can I use my ITIN instead of an EIN to register for sales tax?
Generally no. ITINs are individual income-tax IDs and aren’t accepted as business tax IDs by state sales tax registration portals.
Do I need an EIN if I only sell on Amazon or Walmart?
Possibly not — if 100% of your sales go through marketplaces and you have no other nexus (no FBA inventory in nexus-creating states, no direct sales), you may have no state sales tax registration obligation at all. Run a nexus study before assuming.
What’s the difference between an EIN and a sales tax permit?
The EIN is your federal tax ID issued by the IRS. The sales tax permit is a separate state-level authorization issued by each state’s DOR. The EIN is required to apply for the permit; they’re not the same number.
Which states accept an SSN instead of an EIN for sales tax registration?
A handful of states accept an SSN for US sole proprietors, but the list and portal behavior change. We confirm per-state at the time of registration. Foreign sellers without an SSN can’t use this path regardless.
Can I register in multiple states with the same EIN?
Yes. One EIN is used across all states. Each state issues its own separate sales tax permit number tied to your single federal EIN.
Last verified: 2026-05-10
This article is for informational purposes only and does not constitute tax advice. Consult a licensed tax professional before acting on any of this content.
