What is a PESEL number?

PESEL is the 11 digit national identification number Poland gives to every citizen and registered resident. It is printed on Polish ID cards and passports and used for taxes, health care and banking. The first six digits are the birth date, so the number alone tells you when someone was born and whether the registry lists them as male or female.

The digits follow the pattern YYMMDDZZZXQ:

  • YYMMDD is the birth date. The month also carries the century: 01 to 12 for 1900 to 1999, plus 20 for 2000 to 2099, plus 40 for 2100 to 2199, plus 60 for 2200 to 2299 and plus 80 for 1800 to 1899. So someone born in February 2009 has 22 as the month.
  • ZZZX is a serial number. Its last digit X is even for women and odd for men.
  • Q is the check digit. Multiply the first ten digits by 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, add the results and subtract the last digit of the sum from 10. A result of 10 counts as 0.

Tool description

Type or paste a PESEL and the tool checks it as you type. A valid number needs 11 digits, a real birth date that is not in the future and a matching check digit. When one of these fails, the tool tells you which one.

For a valid number you get the gender, the birth date, the age today and the check digit. The birth date follows the date format in your regional settings. Spaces and hyphens are ignored, and the number never leaves your browser.

Features

  • Checks the length, the birth date and the check digit with the stdnum library
  • Reads the century from the month, so 1800s and 2000s birth dates come out right
  • Shows gender, birth date and age without sending the number anywhere