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EIN Validator

Finance & Global IDs

Validate US Employer Identification Numbers (EIN) for correct XX-XXXXXXX format instantly. Checks structure and prefix — free, client-side, nothing stored.

Reviewed by the thecalcu.com team · Last updated July 25, 2026

What is a EIN?

An EIN Validator checks whether a US Employer Identification Number is shaped correctly, nine digits, split as a 2-digit prefix and a 7-digit sequence, written XX-XXXXXXX. The IRS assigns EINs to identify businesses, trusts, and other legal entities for federal tax purposes, and getting the structure wrong on a form is one of the more common (and easily preventable) reasons a 1099 filing or vendor record gets kicked back.

The check runs in three steps: confirm the input is exactly 9 digits after stripping any hyphens or spaces, confirm the first two digits match a prefix the IRS has actually assigned (not every two-digit code from 00–99 is in use), and format the result as XX-XXXXXXX. This is a structural check, not a lookup, it can't tell you whether a specific EIN belongs to a real, currently active business, only whether the number is shaped the way a real one would be.

Everything runs client-side. The EIN you type never leaves your browser or touches a server, which matters given that it's a sensitive business identifier.

Common Reasons This Validator Fails

Wrong digit count. The most frequent failure by far, 8 or 10 digits instead of 9, usually from a copy-paste that dropped or duplicated a character.

An unassigned prefix. Codes like 00, 07–09, 17–19, 28, and 49 were never issued as IRS campus codes. If you see one of these fail, double-check the source document, it's often a sign the number was transcribed wrong, not that the format rule is being too strict.

An SSN entered into the EIN field. Both are 9 digits, but an SSN is grouped 3-2-4 (XXX-XX-XXXX) while an EIN is grouped 2-7 (XX-XXXXXXX). Someone filling out a form for a sole proprietorship will sometimes paste their SSN where an EIN was expected, the digit count matches, so it's an easy mistake to make and an easy one for this tool to catch.

Assuming validity means the business is real. A structurally valid EIN, right length, right prefix, isn't proof the number is actually registered or active. That distinction matters if you're using this as a first-pass filter before a more authoritative check, like requesting a W-9 directly from the vendor.

Who Should Use This Validator?

Bookkeepers and accountants entering vendor EINs ahead of 1099-NEC season, where a malformed number means a rejected e-file later.

HR and contractor-onboarding platforms collecting W-9 information from US vendors and freelancers, where catching a bad EIN at data entry beats discovering it during a payroll run.

Developers building payroll, invoicing, or tax-compliance tools who want input-level validation before an EIN hits a database, pair with the EIN Formatter to normalize raw digit strings before validating them, or with the SSN Validator if the same form also collects personal tax IDs.

Show formula & methodology ↓Show less ↑

Formula & Methodology

The check applies these rules in order:

1. Strip everything except digits from the input.
2. Confirm exactly 9 digits remain.
3. Confirm the first two digits are a valid IRS campus prefix, specifically not one of: 00, 07–09, 17–19, 28, 49, 69, 70, 78, 79, 89, 96, 97.
4. Format the result as XX-XXXXXXX.

There's no checksum digit involved, unlike some ID formats (IBAN, credit card numbers), an EIN has no built-in mathematical check digit, so structure and prefix are the only two things a format validator can verify.

Quick Reference

EIN Valid? Why
12-3456789 ✓ Correct length, valid prefix
123456789 ✓ Hyphen is optional
00-1234567 ✗ Prefix 00 was never assigned
12-345678 ✗ Only 8 digits
123-45-6789 ✗ SSN grouping, not EIN grouping

For related US identifiers, see the SSN Validator for personal tax IDs or the VAT Number Validator for EU/UK business tax numbers. If you're working with India's equivalent business identifier instead, the PAN Number Validator checks that format.

Frequently Asked Questions

What is an EIN?
An Employer Identification Number is a 9-digit code the IRS assigns to identify a business entity for federal tax purposes, it's also called a Federal EIN or Federal Tax ID Number. Think of it as the business equivalent of a Social Security Number: it shows up on tax filings, payroll records, business bank accounts, and vendor paperwork. Every US corporation, partnership, and most LLCs need one.
What format does an EIN follow?
Nine digits written as XX-XXXXXXX, a 2-digit prefix, a hyphen, then a 7-digit sequence. 12-3456789 and 98-7654321 are both correctly shaped examples. The prefix isn't arbitrary; it identifies which IRS campus processed the application, though not every two-digit combination from 00 to 99 is actually in use.
What do the first two digits of an EIN actually mean?
They identify the IRS Campus, formerly called a Service Center, that issued the number, 01 is Andover, Massachusetts; 02 is Atlanta, Georgia, and so on. They tell you nothing about where the business is physically located, which surprises people who assume the prefix is a state or region code. A handful of prefixes (00, 07–09, 17–19, 28, 49, and a few others) were never assigned and immediately flag an invalid EIN.
How is an EIN different from a Social Security Number?
An SSN identifies a person and is formatted XXX-XX-XXXX; an EIN identifies a business, trust, or other legal entity and is formatted XX-XXXXXXX. Both are issued by different agencies too, SSNs come from the Social Security Administration, EINs from the IRS. Sole proprietors sometimes use their own SSN for business purposes instead of getting an EIN, which is one reason the two formats occasionally get confused on forms.
Does passing this check mean the EIN is real and active?
No. This tool validates structure only, nine digits, correct grouping, and a prefix that maps to a real IRS campus. It has no way to confirm the number was actually issued or is currently active with the IRS, since that requires querying IRS systems directly (through EFTPS or a 147C letter request), which isn't something a client-side format check can do.
Is the EIN I enter sent anywhere or stored?
No, everything happens locally in your browser. Nothing is transmitted to a server, logged, or saved anywhere, which matters given that an EIN is a sensitive business identifier you generally don't want passing through third-party services unnecessarily.
Who typically needs to check an EIN's format?
Bookkeepers and accountants entering vendor EINs before filing 1099s, HR platforms onboarding contractors who submit W-9 forms, and developers building payroll or invoicing software who want to catch obviously malformed input before it reaches a database. It's a first-pass sanity check, not a substitute for the IRS's own records.
How does an EIN compare to a VAT number?
They serve a similar administrative purpose, identifying a business for tax purposes, but come from completely different systems. A VAT number is used across the EU and UK for value-added tax and follows country-specific formats; an EIN is strictly a US federal tax identifier with one fixed 9-digit shape. A company trading in both the US and Europe may hold both. Check VAT structure separately with the [VAT Number Validator](/vat-number-validator/).
How do I use the EIN Validator?
Type the EIN into the field, with or without the hyphen, 12-3456789 and 123456789 both work. The tool strips anything that isn't a digit, confirms there are exactly nine of them, and checks that the first two form a recognized IRS prefix. The result updates as you type, no submit button required.
Where would I actually find a company's EIN?
It appears on IRS Form W-9, Form 1099, Form W-2, business tax returns, and bank account paperwork. Publicly traded companies also disclose their EIN in SEC filings like the 10-K, searchable through SEC EDGAR. There's no requirement for a private company to publish its EIN, so you'll usually need to ask them directly or check a document they've already sent you.
Do non-profits use a different EIN format?
No, a 501(c)(3) or other tax-exempt organization gets the same XX-XXXXXXX structure as any for-profit business. The format itself doesn't signal non-profit status one way or another. What is useful is that non-profit EINs are searchable via IRS Form 990 filings, publicly available through the IRS website or ProPublica's Nonprofit Explorer.
Also known as
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