What Is a Tax ID Number Used for?

A taxpayer identification number (TIN) is an identification number used by the Internal Revenue Service (IRS) to identify individuals, businesses or tax preparers for tax purposes. Individual taxpayer numbers can be issued by the Social Security Administration or the IRS.

Social Security Number (SSN)

A Social Security number identifies U.S. citizens and legal aliens and is issued by the Social Security Administration.

Individual Taxpayer Identification Number (ITIN)

An individual taxpayer identification number, issued by the IRS, is used for federal tax reporting for nonresident and resident aliens, their spouses and dependents.

Employer Identification Number (EIN)

An employer identification number (EIN) is used to identify a business and issued by the IRS.

Adoption Taxpayer Identification Number (ATIN)

An adoption taxpayer identification number is a temporary number issued by the IRS to individuals in the process of adopting a U.S. citizen or resident child and can't obtain a SSN for the child.

Preparer Taxpayer Identification Number (PTIN)

A preparer taxpayer identification number, issued by the IRS, is for tax preparers who do not want to disclose their SSN on the taxes they prepare.