FEIN vs EIN vs Tax ID: What's the Difference?

Quick answer: A FEIN and an EIN are the same nine-digit number. The F stands for Federal — some forms add it to make clear they want the IRS-issued number rather than a state one, but there is no separate application and no separate number. "Tax ID" is the umbrella term: it covers EINs along with Social Security Numbers (SSNs) and Individual Taxpayer Identification Numbers (ITINs). So yes, your EIN is a tax ID — and when a bank, payment processor, or vendor asks for your business tax ID, the EIN is almost always the number they mean.

This guide walks through FEIN vs EIN, tax ID vs EIN, and where state entity numbers and sales tax IDs fit, so you enter the right number on the right form the first time.

What Does FEIN Stand For?

FEIN stands for Federal Employer Identification Number. It is the same nine-digit number, formatted XX-XXXXXXX, that the IRS assigns to a business entity. You will see it written as EIN, FEIN, federal EIN, or federal tax ID number — all four refer to one number.

FEIN vs EIN: Two Names, One Number

There is no difference between a FEIN and an EIN. The federal label exists because states issue identification numbers of their own — entity numbers for registration, state account numbers for payroll and sales tax — and a form that says FEIN is telling you it wants the federal number, not one of those. If you already have an EIN, you already have a FEIN. You will never apply for one and then need the other.

What Is a Tax ID (TIN)?

A Taxpayer Identification Number (TIN) is any number the IRS uses to identify a taxpayer — an individual or a business — on tax returns and related filings. Tax ID is the category, not a single document. The common types:

• Social Security Number (SSN) — issued by the Social Security Administration for individuals
• Individual Taxpayer Identification Number (ITIN) — for individuals who are not eligible for an SSN
• Employer Identification Number (EIN) — for businesses, nonprofits, trusts, and estates
• Preparer Tax Identification Number (PTIN) — for paid tax preparers
• Adoption Taxpayer Identification Number (ATIN) — for pending domestic adoptions

Are a Tax ID and an EIN the Same Thing?

For a business, in practice, yes. The tax ID number requested on banking, credit, and merchant account applications is the EIN. Strictly speaking, though, an EIN is one type of tax ID rather than a synonym for it. The distinction comes down to three things:

• Scope: Tax ID is the broad category; the EIN is the business-specific type within it. Your SSN is a tax ID, but it is not an EIN.
• Purpose: A tax ID exists for tax reporting generally. An EIN also unlocks business operations — payroll, business banking, licensing, and merchant account underwriting.
• Eligibility: Which tax ID you use depends on who you are. EINs belong to business entities and employers; SSNs and ITINs belong to individuals.

A sole proprietor with no employees can use an SSN as a business tax ID. Most obtain an EIN anyway, to keep personal and business finances separate — and because banks and payment processors typically require one.

TIN vs EIN: Category vs Type

Every EIN is a TIN. Not every TIN is an EIN. When a form asks for a TIN, it is asking for whichever identification number applies to you: an individual supplies an SSN or ITIN, a business supplies its EIN. On a W-9, for example, a corporation or LLC enters its EIN in the TIN field, while a sole proprietor without an EIN enters an SSN. If your business has an EIN, that is the number to use for business filings every time.

Entity Number vs EIN: State Number, Federal Number

An entity number — also called an entity ID, business ID, or charter or file number — is issued by your state, usually the Secretary of State, when you register an LLC, corporation, or other entity. Your EIN is issued by the IRS at the federal level. They are not interchangeable:

• Entity number: state-level filings such as annual reports, franchise tax, and registered agent updates
• EIN: federal taxes, payroll, W-9s and 1099s, business banking, and merchant account underwriting

Most registered businesses have both. If a form asks for your state entity number, do not enter your EIN — and vice versa. Registering with your state does not create a federal tax ID, so a new entity still needs to obtain an EIN separately.

Is a Sales Tax ID the Same as an EIN?

No. A sales tax ID — sometimes called a seller's permit or sales tax permit — is issued by your state and authorizes you to collect and remit sales tax there. Your EIN is federal and has nothing to do with sales tax registration. A business that sells taxable goods typically holds both numbers, obtained through two separate applications.

Where Do I Find My Tax ID?

If your business already has an EIN, you can find it in several places:

• The IRS confirmation letter (CP 575) issued when the EIN was assigned
• A previously filed federal tax return for the business
• Your business bank, which collected the EIN when the account was opened
• The IRS directly, if none of the above are available

Keep the CP 575 letter somewhere safe. Banks and payment processors often request it during underwriting, and replacing it takes longer than finding it.

How to Get an EIN

An EIN is free, directly from the IRS:

• Online — the fastest option; you receive your EIN immediately during operating hours
• Fax — submit Form SS-4; processing takes about four business days
• Mail — allow up to four weeks
• Phone — available for international applicants

Protect your EIN as carefully as you would an SSN. For other tax IDs: SSNs come from the Social Security Administration, ITINs from the IRS via Form W-7, and PTINs through IRS registration for paid preparers.

Why Your EIN Matters for Payment Processing

When you apply for a merchant account, underwriters verify that your legal business name and EIN match IRS records and your business bank account. A missing or mismatched EIN is one of the most common — and most avoidable — reasons applications stall. That is doubly true where underwriting is stricter: if you are applying for a high-risk merchant account, have your EIN confirmation letter, formation documents, and matching bank details ready before you apply.

One related number worth separating out: your EIN is not your merchant ID number. The IRS assigns the EIN before you apply; your processor assigns the merchant ID once your account is approved, and it identifies your business on the card networks rather than with the IRS. If you operate in one of the high-risk industries we serve, our team can tell you exactly which documents underwriters will expect.

The Bottom Line

FEIN and EIN are one number with two names. "Tax ID" is the umbrella that covers it, along with SSNs and ITINs. Add your state entity number for state filings and a sales tax ID if you sell taxable goods, and you have the complete picture. Keeping these numbers consistent across the IRS, your bank, and your processor helps keep compliance clean and merchant approvals on track.

Ready to put your EIN to work? We help businesses in hard-to-place industries get approved for payment processing. Contact us to get started.