Every Employer Identification Number starts with a two-digit prefix somewhere between 01 and 99. That prefix identifies the IRS campus that issued the number, shows it was assigned through the IRS online application, or — in one case — points to the Small Business Administration.1Internal Revenue Service. Valid EINs The remaining seven digits are assigned sequentially and carry no meaning about the business.
How an EIN Is Formatted
An EIN is a nine-digit number written as XX-XXXXXXX, with a hyphen after the second digit.2eCFR. 26 CFR 301.6109-1 – Identifying Numbers That layout distinguishes it at a glance from a Social Security Number, which uses a three-two-four pattern (XXX-XX-XXXX).3Social Security Administration. SSN – Order of Issuance
Only the first two digits carry information. They tie back to the IRS campus that processed the paperwork or indicate the number came from the online portal. The seven digits after the hyphen simply count upward within that prefix pool.
The Complete List of Valid EIN Prefixes
The IRS publishes an official table of every valid two-digit prefix and the campus or method it corresponds to.1Internal Revenue Service. Valid EINs If your EIN begins with a two-digit number that is not on this list, it is not a valid EIN prefix.
- Andover: 10, 12
- Atlanta: 60, 67
- Austin: 50, 53
- Brookhaven: 01, 02, 03, 04, 05, 06, 11, 13, 14, 16, 21, 22, 23, 25, 34, 51, 52, 54, 55, 56, 57, 58, 59, 65
- Cincinnati: 30, 32, 35, 36, 37, 38, 61
- Fresno: 15, 24
- Kansas City: 40, 44
- Memphis: 94, 95
- Ogden: 80, 90
- Philadelphia: 33, 39, 41, 42, 43, 46, 48, 62, 63, 64, 66, 68, 71, 72, 73, 74, 75, 76, 77, 85, 86, 87, 88, 91, 92, 93, 98, 99
- Internet (online applications): 20, 26, 27, 33, 39, 41, 45, 46, 47, 81, 82, 83, 84, 85, 86, 87, 88, 92, 93, 99
- Small Business Administration (SBA): 31
What the Prefix Actually Tells You
Historically, the IRS assigned prefixes based on where the business was located. Paper applications went to a regional campus, and each campus drew from its own pool of two-digit numbers. That geographic link has faded as the IRS shifted most processing to its online system and consolidated campus workloads. Today, the prefix reveals how the EIN was processed, not where the business sits.
Shared Prefixes Between a Campus and the Internet
Several prefixes appear under both a physical campus and the Internet category. Numbers 33, 39, 41, 46, 85, 86, 87, 88, 92, 93, and 99 are listed under both Philadelphia and Internet.1Internal Revenue Service. Valid EINs If your EIN begins with one of those, you cannot tell from the prefix alone whether it was assigned at a campus or through the online tool.
The One SBA Prefix
Prefix 31 is the only one tied to the Small Business Administration rather than an IRS campus or the online system.1Internal Revenue Service. Valid EINs EINs beginning with 31 were assigned through the SBA rather than the standard IRS application process.
Prefixes for EINs Assigned Online
Most new EINs today come from the IRS online application, which draws from a centralized pool of prefixes rather than any regional campus. The Internet prefixes are 20, 26, 27, 33, 39, 41, 45, 46, 47, 81, 82, 83, 84, 85, 86, 87, 88, 92, 93, and 99.1Internal Revenue Service. Valid EINs
The IRS has expanded this pool over time. Prefixes 33 and 39 were added to the Internet assignment list in late 2024 and mid-2025, respectively.4Internal Revenue Service. 21.7.13 Assigning Employer Identification Numbers (EINs) A business owner anywhere in the United States or its territories receives a prefix from the same Internet pool regardless of where they are located.
Not every applicant can use the online system. You must have a legal residence, principal place of business, or principal office in the United States or a U.S. territory, and the responsible party listed on the application must have a valid SSN, ITIN, or EIN.5Internal Revenue Service. Instructions for Form SS-4 Applicants who do not meet those requirements apply by fax, mail, or, for international applicants, by phone.
Prefix 98 for International Entities
Foreign entities with no legal residence or principal office in the United States receive prefix 98.4Internal Revenue Service. 21.7.13 Assigning Employer Identification Numbers (EINs) That group includes corporations incorporated in a foreign country and other organizations based outside the U.S. that still have federal tax obligations, such as businesses earning U.S.-sourced income or those subject to withholding requirements.
Mailed and faxed applications from foreign entities are processed exclusively by the IRS Cincinnati International Unit. Phone requests are handled by both the Cincinnati and Ogden International Units.4Internal Revenue Service. 21.7.13 Assigning Employer Identification Numbers (EINs) International applicants can call 267-941-1099 (not toll-free) Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern Time.6Internal Revenue Service. Employer Identification Number Foreign entities may also fax Form SS-4 to 855-215-1627 (within the U.S.) or 304-707-9471 (outside the U.S.).
What the Prefix Does Not Reveal
A prefix does not tell you where the business currently operates, when the EIN was issued, or anything about the entity type. Because prefixes are shared across campuses and the online system, and because the online pool is fed to applicants nationwide, the two-digit number should not be read as a location code. It is a record of how the application was processed and nothing more.
The EIN itself, once assigned, becomes the entity’s permanent federal taxpayer identification number and stays linked to that entity even if the business closes. It is never reassigned to another organization.7Internal Revenue Service. If You No Longer Need Your EIN So the prefix on any given EIN reflects the moment that specific number was issued to that specific entity, and nothing about the number changes afterward.