What is a Social Security Number (SSN)?
The Social Security Number (SSN) represents a distinctive 9-digit numerical identification sequence based on the XXX-XX-XXXX format.
The Social Security Administration issues SSNs to U.S. citizens and permanent residents along with selected nonresident aliens using parentheses around the middle two sections that establish the precise nine-digit number (XXX-XX-XXXX). The IRS relies on SSNs as the primary Taxpayer Identification Number (TIN) for individuals to file federal income tax returns.
- Individuals need to inform the IRS about their wages, together with self-employment income and all other income.
- Taxpayers can claim dependents and eligible tax credits, including the Earned Income Tax Credit.
The identification number 123-45-6789 serves as a common identifier, which enables the IRS and SSA to match records correctly for tax and benefit purposes.
Who Needs an SSN?
A Social Security Number (SSN) is essential for:
- U.S. Citizens and Permanent Residents: Permanent residents of the U.S., along with all filing taxpayers and dependent claimants, need to maintain SSNs for their records.
- Nonresident Aliens: Nonresident foreign individuals who work in the U.S. or file to recuperate tax refunds must possess a valid SSN unless ineligible, for which they would need an ITIN.
- Dependents: The children or dependents who qualify for tax benefits, including Child Tax Credit, need an SSN unless specific criteria apply. For example, in the case of certain adopted children, an SSN is required.
How to Obtain an SSN
The Social Security Administration functions as the SSN issuer through a three-stage procedure.
Eligibility: U.S. citizens, together with lawful permanent residents and individuals with work authorization through a visa, can seek SSN eligibility.
- Application (Form SS-5): To obtain an SSN, people need to submit their SS-5 application through an SSA office or directly at ssa.gov.
- Required Documents: The required proof includes valid identification such as a passport or driver’s license together with age evidence through a birth certificate and immigration documentation such as I-551 for permanent resident status.
- Processing: After completing an SSN application, users typically receive their number in 2-4 weeks through mail delivery of their Social Security card.
How to get an SSN for newborns?
You can apply for an SSN for your newborn at the hospital when you apply for the birth certificate.
Note: The IRS recommends people submit their application early for obtaining an SSN because tax returns need SSN inclusion by filing deadlines (such as April 15, 2025, for tax year 2024).
Purpose of SSN
- Employers and payers document their payments (interest, dividends) to the IRS using Form W-2 and the SSN information of the employee.
- The social security number enables correct record matching between individual tax documents and personal accounts to stop inaccurate information and fraud.
- SSN is necessary for accessing social security benefits and other government services.
- It is also used for opening bank accounts, applying for loans, and other financial activities.
Special Cases and Alternatives
- Dependents Without SSNs: Newborns must have an SSN by the filing deadline to be claimed; late applications may delay credits unless Form 1040X is filed later.
- Nonresident Aliens: Those ineligible for an SSN (e.g., no work authorization) apply for an ITIN via Form W-7 to file taxes or claim treaty benefits.
- Lost or Stolen SSNs: Replacement cards are requested from the SSA; the IRS advises safeguarding SSNs to prevent identity theft.
Protecting Your SSN
The IRS stresses SSN security due to its role in tax fraud:
- Identity Theft Risk: Criminals use stolen SSNs to file fraudulent returns, claiming refunds. In 2023 alone, the IRS stopped over $6 billion in such fraud.
- Safeguards: Publication 4557 recommends not sharing SSNs unnecessarily, using secure filing methods (e.g., e-file with 2FA), and monitoring tax accounts.
- IRS Response: If an SSN is compromised, taxpayers can request an Identity Protection PIN (IP PIN) via irs.gov to lock their account.
SSN Validation and Errors
The IRS validates SSNs against SSA records:
- Employers and payers can use TIN matching services to verify SSNs, reducing filing errors.
- Enrolled private companies, state, and local government agencies can verify SSNs through consent-based social security number verification (CBSV).
Rejections
Returns with mismatched or invalid SSNs (e.g., typos) are rejected, requiring correction via paper filing or amended returns.
For instance, if “123-45-6789” is entered as “123-54-6789,” the IRS flags it, delaying processing until corrected and may impose a penalty of $50 for each incorrect SSN.