Taxpayer Identification Number (TIN) Definition

A TIN is a nine-digit account number representing a person or business for the IRS. This can be a Social Security number (SSN), Employer Identification Number (EIN), or an Individual Taxpayer Identification Number (ITIN).

Taxpayer Identification Number Extended Definition
For individuals, the Taxpayer Identification Number (TIN) is their Social Security Number (SSN). For employers, the taxpayer identification number is their Employer Identification Number (EIN).

Individuals and businesses must file taxes under their TIN. In addition to being a necessary identifier when filing taxes, this number is also required when opening bank accounts.

Last Updated By

Rachel Blakely-Gray | May 01, 2023

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