Taxpayer Identification Number

This article is about identification numbers used in the US tax system. For taxpayer identification numbers used in other countries, see National identification number. For other types of identifying numbers, see UID (disambiguation).
Not to be confused with Personal identification number.

A Taxpayer Identification Number (TIN) is an identifying number used for tax purposes in the United States and in other countries under the Common Reporting Standard. In the United States it is also known as a Tax Identification Number (TIN) or Federal Taxpayer Identification Number (FTIN). A TIN may be assigned by the Social Security Administration (SSA) or by the Internal Revenue Service (IRS).