What is a Social Security number (SSN) and what is a Social Security card? What is the difference and do I need both?
If you were born in the U.S., and your birth was reported, the government assigned you a Social Security number (SSN). Your SSN is a 9-digit number that is unique to you. The government uses it primarily to identify you, but also to track your income for tax purposes and to calculate any Social Security benefits you accrue as you work. Also, other institutions—like banks, hospitals, schools, and businesses—will use your SSN as a way to identify you.
A Social Security card is a paper card that provides a record of your name and SSN. Social Security cards are issued only by the Social Security Administration of the federal government. Social Security cards are always free.
While there are many circumstances in which you will need to provide your SSN, you will only need to show the actual Social Security card in a few limited situations—most commonly, when filling out employment paperwork. For this reason, it is a good idea to memorize your SSN, but store your Social Security card in a safe place and only carry it with you when you know you’ll need it.