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Social Security Number Definition

A Social Security number, or SSN, is a unique nine-digit number assigned to each person in the Social Security system. The format is XXX-XX-XXXX.

Social Security Number Extended Definition

Social Security numbers are a type of taxpayer identification number (TIN). Individuals use their SSNs to file their taxes.

Some business owners use their SSNs for business tax filing, but many businesses, including employers and corporations, need an Employer Identification Number (EIN) for tax purposes.

Last Updated By

Rachel Blakely-Gray | May 01, 2023

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