Per the IRS How EINs are Assigned and Valid EIN Prefixes webpage, the prefix for an EIN number indicates which campus assigned it. Valid EIN numbers start with the following prefixes.
| Campus/ Other Location | Valid EIN Prefixes |
| 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 | 20, 26, 27, 45, 46, 47, 81, 82, 83, 84, 85 |
| Small Business Administration (SBA) | 31 |
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.