A tax identification number (TIN), also known as a taxpayer identification number, is a unique identifier used by tax authorities to identify taxpayers. For individuals, it is typically a social security number (SSN) or individual taxpayer identification number (ITIN). For businesses, it is typically an employer identification number (EIN).
TINs are used to identify taxpayers and track their tax payments. They are also used to verify the identity of taxpayers and to prevent fraud. The use of TINs has become increasingly important in recent years as the IRS has stepped up its efforts to combat tax fraud and identity theft.
