US EIN Format Validator
Enter a US Employer Identification Number (EIN) to check that it has nine digits in the NN-NNNNNNN format and a valid IRS prefix. This checks the format only. It does not confirm the EIN is registered to a business.
Processed entirely in your browser. This validator runs on your device using JavaScript. The number you enter is never sent to a server, stored, or logged, and nothing leaves your device.
How It Works
An Employer Identification Number is the tax ID the IRS gives a business, the way a Social Security Number identifies a person. It is nine digits, written with a dash after the first two, as NN-NNNNNNN.
| Part | Digits | What it is |
|---|---|---|
| Prefix | 2 | The IRS campus or method (such as the online application) that assigned the EIN |
| Serial | 7 | The rest of the number, unique within that prefix |
The tool checks that there are exactly nine digits and that the first two are a prefix the IRS actually uses. The IRS only issues EINs from a set list of prefixes, so a number with a prefix outside that list cannot be a genuine EIN. It does not, and cannot, confirm that the EIN is registered to a real business, because there is no public database of every issued EIN.
Worked Example
Take the sample number 12-3456789, which is made up rather than a real business EIN. The prefix is 12, which is on the IRS list, and there are nine digits in total, so it passes the format check. A number like 07-1234567 would fail, because 07 is not a prefix the IRS assigns.
How to Find Your EIN
If you have misplaced your EIN, you do not need to apply for a new one. It is recorded in several places you can usually reach quickly:
- The IRS confirmation notice (CP 575) you received when the EIN was first issued. This is the original source.
- A previously filed business tax return. The EIN is printed at the top.
- The paperwork for a bank account, loan, or licence opened under the business, which almost always records the EIN.
- Older IRS notices or letters addressed to the business.
- If none of those work, call the IRS Business and Specialty Tax Line and, after they verify you are authorised, they can give it to you over the phone.
When You Would Use This
Business owners, bookkeepers, and anyone filling in a W-9 or a tax form use this to confirm an EIN is written correctly before it goes on paperwork, since a transposed digit can hold up a filing. It is also a quick sanity check when you are copying an EIN from one document to another and want to be sure the format and prefix are right.
Frequently Asked Questions
What is the difference between an EIN, an SSN, and a TIN?
TIN, or Taxpayer Identification Number, is the umbrella term. An EIN is the TIN for a business. An SSN is the TIN for an individual. All three are nine digits, but an EIN is written NN-NNNNNNN while an SSN is written NNN-NN-NNNN.
Is an EIN public information?
Often, yes. Unlike an SSN, a business EIN is not treated as a secret. It appears on public filings, W-9 forms, and business documents, and non-profit EINs are searchable in IRS tax-exempt records. It should still be handled with care.
Can I verify another company's EIN with this tool?
Only its format. This tool confirms a number is shaped like a real EIN and uses a valid IRS prefix. It cannot tell you which business an EIN belongs to, because there is no public master lookup of every EIN.
What makes an EIN format invalid?
Two things: the wrong number of digits, or a first two digits that the IRS does not use. The IRS assigns EINs from a specific set of prefixes tied to the campus or method that issued them, so a prefix outside that set cannot be a real EIN.
Is my EIN sent anywhere when I check it?
No. The check runs entirely in your browser. Nothing you type is transmitted, stored, or logged.