|This article is part of a series on|
|Taxation in the United States|
|United States portal|
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 or Federal Taxpayer Identification Number. A TIN may be assigned by the Social Security Administration or by the Internal Revenue Service (IRS).