US EIN Validator
Online validator for US Employer Identification Numbers (EIN) according to official IRS specifications.
How does EIN validation work?
EIN validation checks total length (9 numeric digits), masking (XX-XXXXXXX or 9 digits continuous), and ensures the first 2 digits match official IRS campus/channel prefixes.
If the number has fewer than 9 digits, a serial of all zeros (0000000), or a prefix prohibited/never issued by the IRS (such as 00, 07, 17, 28, 49, etc.), it is marked as invalid.
Anatomy & Structure of EIN (9 Digits: XX-XXXXXXX)
The IRS Employer Identification Number is structured into 2 distinct sections:
| Position | Field | Length | Meaning & Rule | Example |
|---|---|---|---|---|
| 1 & 2 | Campus Prefix | 2 digits | IRS regional processing center code or Internet application channel | 12 |
| 3 to 9 | Registration Serial | 7 digits | Unique sequential identifier issued to the business entity | 3456789 |
EIN Validation Rules (IRS Guidelines)
EIN verification validates format, non-zero serials, and authorized IRS campus prefixes:
Prefix in ValidPrefixesList && Serial != 0000000
- 1. Strip formatting to retain exactly 9 numeric digits.
- 2. Confirm total length is exactly 9 digits.
- 3. Extract the 2-digit prefix (positions 1 and 2).
- 4. Verify the prefix belongs to the authorized IRS campus mapping.
- 5. Reject forbidden IRS prefixes (00, 07, 08, 09, 17, 18, 19, 28, 29, 49, 69, 70, 78, 79, 89, 96, 97).
- 6. Verify the 7-digit serial is not entirely zeros (0000000).