A Taxpayer Identification Number (TIN) is an identification number used by the Internal Revenue Service (IRS) in the administration of tax laws. It is issued either by the Social Security Administration (SSA) or by the IRS.  A Social Security Number (SSN) is issued by the SSA, whereas all other TINs are issued by the IRS.

Different types of Taxpayer Identification Numbers:
  • Social Security Number (SSN)
  • Employer Identification Number (EIN)
  • Individual Taxpayer Identification Number (ITIN)
  • Taxpayer Identification Number for Pending U.S. Adoptions (ATIN)
  • Preparer Taxpayer Identification Number (PTIN)