A Tax Identification Number (TIN) is a unique identifier assigned to individuals and businesses for tax purposes. It helps the Internal Revenue Service (IRS) track tax obligations and ensure compliance with tax laws. TINs can take various forms, including Social Security Numbers (SSNs) for individuals and Employer Identification Numbers (EINs) for businesses. Having a TIN is essential for filing tax returns, opening bank accounts, and applying for loans. It helps prevent identity theft and ensures that taxpayers are accurately identified in the tax system. Overall, a TIN is a crucial component of the tax process in the United States.