A TIN, or Taxpayer Identification Number, is an exclusive numerical identification given by tax authorities to individuals, businesses, or entities for tax-related reasons. In the United States, an individual's TIN is frequently their Social Security Number (SSN), while businesses utilize an Employer Identification Number (EIN). Globally, TINs fulfill comparable roles, allowing tax authorities to monitor and administer taxpayer responsibilities. The precise structure and vocabulary of TINs can differ across countries.