One number
SSN Validator
Check one Social Security Number for format and reservation rules.
Tools
Choose a checker below. Digits stay in this browser, and none of these tools replace SSA SSNVS or E-Verify.
Up to 200
Bulk SSN Validator
Paste a list and classify up to 200 numbers in this browser.
AAA-GG-SSSS
SSN Structure
Split a number into area, group, and serial, and see what those parts meant before 2011.
Pre-2011 chart
SSN Area Numbers
Look up historic area bands for states, territories, railroad, and Enumeration at Entry.
Identifier types
SSN vs ITIN vs EIN
Tell personal, taxpayer, and employer identifiers apart.
2026 wage base
FICA Tax Calculator
Social Security wage base $184,500 plus Medicare math.