EIN Number Format: What a Valid EIN Looks Like
An EIN carries 9 digits in XX-XXXXXXX form: a 2-digit IRS campus prefix and a 7-digit sequence, joined by 1 hyphen. The IRS uses 60 assigned prefixes and leaves 13 unassigned.
This page prints the structure, the prefix list, the SSN comparison, and 4 flags for spotting a fake EIN before it hits a W-9 or a payroll file.
What is the EIN number format?
9 digits total, printed as XX-XXXXXXX. Example: 12-3456789. The IRS assigns EINs under 26 U.S.C. § 6109 and has kept the same 2-7 hyphenated structure since 1974. Databases store 9 digits with 0 punctuation; the CP-575 letter prints the hyphenated form.
What do the first 2 digits of an EIN mean?
The 2-digit prefix marks the IRS campus that assigned the EIN. Before 2001 the prefix mapped to a geographic office (10 to 89 across 12 campuses). Since 2001 the IRS reassigns prefixes across campuses; the prefix no longer marks a location. 60 prefixes are active; 13 are unassigned.
| Prefix band | Historical campus |
|---|---|
| 10 - 16 | Andover (MA), Atlanta (GA) |
| 20 - 27 | Kansas City (MO) |
| 30 - 48 | Cincinnati (OH), Memphis (TN) |
| 50 - 77 | Ogden (UT), Philadelphia (PA) |
| 80 - 88 | Internet EIN assistant |
| 90 - 99 | Small Business Administration overflow |
How does the EIN format differ from an SSN?
Both are 9 digits, but the punctuation and structure differ. SSN prints XXX-XX-XXXX (3-2-4 with 2 hyphens). EIN prints XX-XXXXXXX (2-7 with 1 hyphen). Confusing the 2 triggers IRS mismatches on 1099 and W-2 filings; the IRS returns error notice CP-2100 within 6 to 8 weeks.
| Attribute | EIN | SSN |
|---|---|---|
| Digits | 9 | 9 |
| Hyphens | 1 | 2 |
| Structure | 2-7 | 3-2-4 |
| Assigned to | Entity | Individual |
| Issuer | IRS | Social Security Administration |
The full split between the 2 IDs sits on the EIN vs SSN page.
How do you spot a fake EIN number?
Run 4 checks: 9-digit length, valid prefix, XX-XXXXXXX format, and match to CP-575 or 147C. A number with 8 or 10 digits is not an EIN. A prefix of 00, 07, 08, 09, 17, 18, 19, 28, or 29 signals a fake or typo. 1 mismatch on the CP-575 letter kills the check.
Which EIN prefixes are unassigned?
13 prefixes as of July 2026: 00, 07, 08, 09, 17, 18, 19, 28, 29, 49, 78, 79, and 89. A 9-digit number that starts with any of the 13 is not a valid EIN. The other 60 prefixes span 10 to 99 with the 13 gaps and route to active IRS campuses.
How do you verify an EIN format before submitting?
3 checks in 30 seconds: 9 digits total, prefix on the 60-prefix valid list, and XX-XXXXXXX print form. Compare to the CP-575 letter for your own EIN. Request a 147C by calling 267-941-1099 if the CP-575 is lost; the 147C returns by fax within 1 to 2 business days.
For vendor EINs, W-9 line 7 carries the 9-digit value; the requester matches format character by character. Public companies list the EIN on SEC filings: search EDGAR by ticker. Read the find EIN for a business page for the vendor lookup path.
What else do people ask about EIN format?
10 more questions about the 9-digit XX-XXXXXXX structure. The IRS uses 60 valid prefixes and leaves 13 unassigned. Verify vendor EINs against the CP-575 letter or a 147C request in 1 IRS call.
How many digits are in an EIN number?
An EIN is 9 digits total, split into a 2-digit prefix and a 7-digit sequence. The format prints as XX-XXXXXXX with 1 hyphen. That structure has held since the IRS began issuing EINs in 1974. A 9-digit number without the hyphen is still a valid EIN; databases store 9 digits with 0 punctuation.
What does the 2-digit EIN prefix mean?
The 2-digit prefix marks the IRS campus that assigned the EIN. Since 2001, the IRS reassigned prefixes to any campus; the prefix no longer identifies a geographic office. The IRS maintains a public list of 60 valid prefixes. Prefixes 00, 07, 08, 09, 17, 18, 19, 28, 29, 49, 78, 79, and 89 are unassigned.
What does a valid EIN look like?
A valid EIN carries 9 digits in XX-XXXXXXX form. Example: 12-3456789. The first 2 digits are 1 of the 60 IRS-assigned prefixes. The final 7 digits are a sequence with 0 check digits. Banks and payroll providers accept 9 digits with or without the hyphen; the CP-575 letter prints the hyphenated form.
How do I spot a fake EIN number?
Check 4 flags: 9-digit length, valid prefix, XX-XXXXXXX format, and match to CP-575. A number with 8 digits or 10 digits is not an EIN. A prefix of 00 or 07 signals a fake or a typo. Cross-reference vendor EINs via a W-9 request or SEC EDGAR; verify your own via a 147C letter from 267-941-1099.
Is an EIN the same format as an SSN?
Both are 9 digits, but the punctuation and structure differ. SSN prints XXX-XX-XXXX (3-2-4 pattern). EIN prints XX-XXXXXXX (2-7 pattern). 1 hyphen versus 2. Some databases strip punctuation, leaving 9 raw digits; the field label (EIN vs SSN vs TIN) disambiguates. Confusing the 2 triggers IRS mismatches on 1099 and W-2 filings.
Can 2 businesses share an EIN?
No. The IRS issues 1 EIN per entity. A single-member LLC filed with 1 EIN owns that EIN for the life of the entity. Parent-subsidiary structures require separate EINs, 1 per legal entity. Sole proprietors with 2 businesses may use 1 EIN across both; the IRS treats sole proprietor and owner as 1 taxpayer under Section 6109.
Where does the EIN print on IRS documents?
The CP-575 confirmation letter prints the EIN in the top-right block in bold XX-XXXXXXX form. Form 1120, Form 1120-S, and Form 1065 carry the EIN on line B, top-right. Form W-9 puts the EIN on line 7 of Part I. The 147C letter also prints the EIN top-left in bold.
Can I change my EIN number format?
No. The IRS assigns 1 EIN per entity and locks the 9-digit value for the life of the business. Reformatting the display (removing the hyphen, adding spaces) does not change the underlying value. A business that needs a new EIN, after a partnership conversion or ownership change, files Form SS-4 again and receives a different 9-digit sequence.
What EIN prefixes are unassigned?
The IRS lists 13 unassigned prefixes as of July 2026: 00, 07, 08, 09, 17, 18, 19, 28, 29, 49, 78, 79, and 89. A 9-digit number starting with any of the 13 is not a valid EIN. The other 60 prefixes (10 through 16, 20 through 27, 30 through 48, 50 through 77, 80 through 88, 90 through 99) map to active IRS campuses.
How do I verify EIN format before submitting?
Run 3 checks: 9 digits total, prefix in the 60-prefix valid list, and XX-XXXXXXX print form. Compare to the CP-575 letter for your own EIN, or request a 147C by calling 267-941-1099 if the CP-575 is lost. For vendor EINs, W-9 line 7 carries the 9-digit value; the requester matches format character by character.