Which document can be used to verify a taxpayer's Social Security number?

The Social Security card is the definitive document for verifying a taxpayer's Social Security number because it explicitly displays the individual's name alongside their unique Social Security number. This card is issued by the Social Security Administration and serves as the primary proof of a person's Social Security number for tax purposes and various legal and financial transactions.

While other documents may contain the individual's name or related identification information, they do not specifically provide the Social Security number itself. For example, a driver's license and a passport can serve as forms of identification, while a birth certificate establishes a person's identity but does not include any Social Security information. This focus on the authenticity and specificity of the Social Security card makes it the most reliable source for verification in matters related to tax filings and government records.