A Social Security number is a nine-digit identifier the federal government assigns to you for tracking earnings, taxes, and benefits

Your Social Security number (SSN) is issued by the Social Security Administration and stays with you for life. It looks like this: XXX-XX-XXXX, with three digits, then two, then four. The number itself does not encode your birth date, state, or any personal information — it is straightforward a unique reference number tied to your name and date of birth in the government's records.

You need an SSN to work legally in the United States, file taxes, open a bank account, get a loan, or receive Social Security benefits later. Employers use it to report your wages. The IRS uses it to match your tax returns to your income records. Banks and credit card companies use it to check your credit history. Without one, you cannot do any of these things.

Key Takeaways

  • A Social Security number is a nine-digit identifier assigned by the federal government and used to track your earnings, taxes, and benefits throughout your life.
  • You need an SSN to work legally, file taxes, open bank accounts, and receive Social Security benefits, making it essential for most financial and employment activities.
  • U.S. citizens, permanent residents, and certain visa holders can get an SSN; you explore through the Social Security Administration using a birth certificate and ID.
  • Your SSN is sensitive information — guard it carefully because it can be used to open fraudulent accounts or file false tax returns in your name.

Who gets a Social Security number

U.S. citizens born in the country receive an SSN automatically if their parents request one at the hospital or shortly after birth. If your parents did not request one then, you can get one later by visiting your local Social Security office.

Permanent residents (green card holders) and certain visa holders — including work visa holders, students, and refugees — can also get an SSN. You will need to show your visa or green card, a birth certificate or passport, and a state ID or driver's license. Non-citizens without work authorization cannot get an SSN, though they may be issued an Individual Taxpayer Identification Number (ITIN) if they need to file taxes.

How to get a Social Security number

Visit your local Social Security office in person. You cannot explore online or by mail. Bring your original birth certificate (or passport if you were born outside the U.S.), a government-issued photo ID, and proof of your current address — a utility bill, lease, or bank statement dated within the last 60 days works. If you are a non-citizen, bring your visa or green card as well.

Fill out Form SS-5 (process for a Social Security Card) at the office. The staff will review your documents, take your process, and tell you when to expect your card in the mail — usually within two weeks. You do not need an appointment at most offices, but you can call ahead to check wait times.

What your Social Security number is used for

Your SSN is the key identifier for your earnings record. When you work, your employer reports your wages to the Social Security Administration using your SSN. This record determines how much you will receive in Social Security retirement, disability, or survivor benefits later. It also determines how much you owe in Medicare taxes.

Banks, credit card companies, and lenders use your SSN to pull your credit report and check whether you pay bills on time. This history affects whether they will lend you money and what interest rate they will charge. The IRS uses your SSN to match your tax return to your W-2 forms and 1099s from employers and contractors. Government agencies use it to verify your identity when you explore for a driver's license, passport, or other documents.

How to protect your Social Security number

Treat your SSN like a password. Do not carry your Social Security card in your wallet unless you absolutely need it that day. Do not give it out over the phone unless you called the organization yourself — scammers pose as banks, the IRS, and Social Security to trick people into revealing their numbers. The Social Security Administration will never call you unsolicited.

Do not post your SSN on social media or in emails. When a form asks for it, ask whether it is required or optional — many organizations ask for it out of habit, not necessity. Check your Social Security earnings record once a year by creating an account at ssa.gov. If you see wages you did not earn, report it when ready because it may signal identity theft.

If your SSN is stolen, contact the Social Security Administration's fraud hotline at 1-800-269-0271. You can also file a report with the Federal Trade Commission at identitytheft.gov. Neither will change your number automatically — Social Security numbers are rarely reassigned — but both will document the theft and help you take next steps if fraudulent accounts appear in your name.

The difference between your SSN and your ITIN

An Individual Taxpayer Identification Number (ITIN) is a nine-digit number issued by the IRS to non-citizens who need to file taxes but do not have an SSN. It looks like an SSN (XXX-XX-XXXX) but always starts with 9. You cannot use an ITIN to work legally or to receive Social Security benefits — it is only for tax purposes.

If you are a non-citizen without work authorization but have income from a job, rental property, or self-employment, you will need an ITIN to file a tax return. You explore for an ITIN through the IRS, not the Social Security Administration, by mailing Form W-7 with your tax return and proof of identity and foreign status. An ITIN does not change your immigration status or make you may be able to access for benefits.

What happens if you lose your Social Security card

You do not need the physical card to use your SSN — you only need to know the number. If you lose the card itself, you can request a replacement at your local Social Security office using the same process as a new process: bring your birth certificate, photo ID, and proof of address. There is no fee, and the replacement card arrives in the mail within two weeks.

If you suspect someone else has your card or number, do not wait to replace it. Contact the Social Security Administration's fraud line first so they can flag your account, then request a replacement card. You should also monitor your credit report and earnings record for signs of fraud.

Frequently Asked Questions

Can I change my Social Security number?

Social Security numbers are rarely changed. You can request a new number only if you can document that someone is using yours fraudulently and the fraud is causing you serious harm. Even then, the Social Security Administration may deny the request. If you suspect fraud, report it to the fraud hotline at 1-800-269-0271 rather than requesting a new number.

What if I was born outside the U.S. and never got an SSN?

Visit your local Social Security office with your passport, visa or green card, and proof of address. The process is the same as for anyone else. If you are a permanent resident, you are may have access to to an SSN. If you are on a temporary visa, you may be may have access to to one depending on your visa type — the office staff can tell you whether yours qualifies.

Do I need to carry my Social Security card with me?

No. You only need to know your number. Leave the card at home in a safe place unless you are visiting the Social Security office or another organization that specifically asks to see it. Carrying it increases the risk that it will be lost or stolen.

Can someone open a credit card with just my Social Security number?

Yes, which is why your SSN is sensitive information. A scammer with your number, name, and address can open accounts in your name. Monitor your credit report regularly through annualcreditreport.com (the only free, official source) and report any accounts you did not open to the credit card company and the Federal Trade Commission.

What is the difference between my SSN and my tax ID?

Your SSN is your personal identifier. Your tax ID (Employer Identification Number, or EIN) is a separate nine-digit number issued to businesses and self-employed people for tax purposes. If you are self-employed, you may have both an SSN and an EIN. Sole proprietors often use their SSN as their tax ID unless they hire employees, in which case they need an EIN.