Spain NAF / SS Validator
Online Spain NAF / SS validator. Verify format and check digits. Test.
How is the NAF / SS validated?
The NAF is the unique 12-digit number assigned to workers registered in the Spanish Social Security system. It is mandatory for employment in Spain.
This tool generates and validates NAF codes, verifying the last 2 check digits applying the standard Modulo 97 algorithm on the first 10 digits.