What is a tax ID number? It's a unique nine-digit number issued by the Social Security Administration or the IRS to anyone ...

A Taxpayer Identification Number (TIN) is a unique nine-digit number the Internal Revenue Service uses to identify individual taxpayers. A TIN can come in different varieties, including Social ...

SSN is a unique identification number associated with US citizens and some non-Americans living in the country. It has been around since 1936, introduced just a year after the Social Security ...

Companies, like people, are usually known by their names, but people and companies both have other types of identification, often issued by government agencies in the form of identification numbers.

Troy Segal is an editor and writer. She has 20+ years of experience covering personal finance, wealth management, and business news. Somer G. Anderson is CPA, doctor of accounting, and an accounting ...

Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. Pete Rathburn is a copy editor and fact-checker with expertise in economics and personal ...