# TIN formats
Governs `ledger_vault::Tin::new`: a TIN is nine digits; an ITIN begins with 9 and its fourth and fifth digits fall in the ranges below; an SSN or EIN doesn't begin with 9 (a nine-digit number beginning with 9 is in the ITIN series).

## IRS Publication 1915 (Rev. 11-2024), "Understanding Your IRS Individual Taxpayer Identification Number", General Information
Source: <https://www.irs.gov/pub/irs-pdf/p1915.pdf>  
Retrieved: 2026-10-15  
SHA-256 of the retrieved file (`p1915.pdf`): `63a3cf3e79c2e73ed15738d5a0875ffb7496c2309e8c3e085836ade16b2e0920`

> An ITIN is a tax processing number, issued by the Internal Revenue Service, for certain resident and nonresident aliens, their spouses, and their dependents. It is a nine-digit number beginning with the number “9”, has a range of numbers from "50" to "65", "70" to "88", “90” to “92” and “94” to “99” for the fourth and fifth digits and is formatted like a SSN (i.e. 9XX-7X-XXXX).

## Instructions for Form W-7 (Rev. December 2024), What's an ITIN
Source: <https://www.irs.gov/instructions/iw7>  
Retrieved: 2026-10-15  
SHA-256 of the retrieved file (`irs-iw7.html`): `1d674a26a63c34b59a2cb6e34d050a95f744c53ae35ea50172a137298b37a000`

> An ITIN is a nine-digit number issued by the IRS to individuals who are required for federal tax purposes to have a U.S. taxpayer identification number but who don’t have and aren’t eligible to get a social security number (SSN).