Tool description

Validate Finnish social security numbers (henkilötunnus) in real time and reveal the structured details behind each code.

Features

  • Uses the open-source finnish-ssn library for checksum-correct validation
  • Parses birth date, age in years, gender, century sign, individual number, and control digit
  • Highlights invalid inputs immediately so you can correct formatting issues before exporting

Use Cases

  • Double-check Finnish SSNs during user onboarding or KYC procedures
  • QA engineers verifying test fixtures that contain Finnish identity numbers
  • Support teams confirming customer records while troubleshooting account issues

Parsing Details

  • Expected pattern: DDMMYYCZZZQ, where C is the century symbol, ZZZ the individual number, and Q the checksum letter or digit
  • Century symbols map to birth centuries: + = 1800–1899, -, U, V, W, X, Y = 1900–1999, and A, B, C, D, E, F = 2000–2099
  • Individual numbers from 002–899 designate gender parity (even = female, odd = male) while 900+ are reserved special identifiers