National register number check
Check a Belgian national register number and see which birth date and sex it encodes. Runs in your browser only.
Test numbers for developers
Need valid numbers to test a form or software? These are generated at random, are only structurally valid and must never be used to identify a real person.
How is the number built?
The number has 11 digits: YY.MM.DD-SSS.CC. The first 6 digits are the birth date, the next 3 are a sequence number (odd for men, even for women) and the last 2 are check digits.
The check digits are 97 minus the remainder of the first 9 digits divided by 97. For people born in 2000 or later, the digit 2 is placed in front of the 9 digits before the calculation.
BIS numbers, for people who are not in the national register, add 20 or 40 to the month. The national register number is personal data: only use it when you are allowed to.