TINS Inquiry
Lesson 1: What is TINS?
Components of a TIN
The 11-digit TIN is composed of three components:
One-digit PREFIX + Nine-digit BASE NUMBER + One-digit CHECK DIGIT = 11-digit TIN
The following table shows the relationships between these components. All TINs have a system-assigned, algorithm-determined check digit.
| PREFIX USED (one digit) |
TYPE of BASE NUMBER (nine digits) |
CHECK DIGIT ASSIGNED (one digit) |
|---|---|---|
| 1 | EIN | System assigned |
| 2 | SSN/ITIN | System assigned |
| 3 | CPA Generated * | System assigned |
| 7 | System-assigned for SSN & ITIN bases only | System assigned |
Some TINs are created and/or assigned in their entirety by the Comptroller’s office or the TIN system.
To protect SSNs and ITINs, TINS converts numbers with a 2 prefix to an 11-digit system-assigned TIN with a 7 prefix.
* Note: CPA-generated TINs with a 3 prefix are used by the Comptroller’s office for a variety of specific reasons. The Tax Division has used the 3-type number sequences for taxpayer numbers. The Fiscal Management Division issues 3-type numbers for purposes such as temporary TINs and summary numbers.
Next: Learning Check