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PESEL (Polish Powszechny Elektroniczny System Ewidencji Ludności, Universal Electronic System for Registration of the Population) is the national identification number used in Poland since 1979. It always has 11 digits, identifies just one person and cannot be changed to another one.

The PESEL number is mandatory for all permanent residents of Poland and for temporary residents living in Poland for over 2 months. Applicants for Polish citizenship must request a PESEL number together with their passport application.

It has the form YYMMDDZZZXQ, where YYMMDD is the date of birth (with century encoded in month field), ZZZ is the personal identification number, X denotes sex (even for females, odd for males) and Q is a control digit, which is used to verify whether given PESEL can be correct or not. If the PESEL is ABCDEF GHIJK, then one can check if it is a possible valid number by computing

A*1 + B*3 + C*7 + D*9 + E*1 + F*3 + G*7 + H*9 + I*1 + J*3 + K*1

The result of this expression should have zero as the final digit (it has to be divisible by 10). This system works reliably well for catching one-digit mistakes and digit swaps.

For example, social security number 44051401358:

1 * 4 + 3 * 4 + 7 * 0 + 9 * 5 + 1 * 1 + 3 * 4 + 7 * 0 + 9 * 1 + 1 * 3 + 3 * 5 = 101

Calculating modulo sum ​​by 10:

101:10 = 10 remainder = 1

If remainder = 0, the check digit is 0. Where the remainder ≠ 0, the check digit will complement the rest of the 10, which in this example is a 9

10 - 1 = 9

Result 9 ​​is not equal to the last digit social security number, or 8, so the number contains an error.

Birthdates[link]

The PESEL system has been designed to cover five centuries. To distinguish people born in different centuries, numbers are added to the MM field:

• for birthdates between 1900 and 1999 - no change to MM field is made (see below)
• for other birthdates:
  • 1800-1899 - month field is increased by 80
  • 2000-2099 - 20
  • 2100-2199 - 40
  • 2200-2299 - 60

For example, a person born on December 24, 2002 would have a PESEL number starting 023224.

Other identifiers[link]

A similar system of statistical identification numbers exists for businesses, called REGON (from Rejestr Gospodarki Narodowej – Register of the National Economy). Also all business taxpayers (prior to September 2011 – all taxpayers) have a tax identification number called NIP (Numer Identyfikacji Podatkowej).

Individuals in Poland are often asked to provide the number of their national identity card (dowód osobisty) as identification (foreign citizens give their passport number instead). Similarly, businesses and corporations are often required to state the number at which they appear in the register of businesses or similar.

External links[link]

• GUS - Główny Urząd Statystyczny (Central Statistical Office (Poland)) - NIP and REGON validator, and database search.
• PESEL Application Form (PDF) (Ministry of Interior and Administration of the Republic of Poland) (MSWiA) - PESEL Application Form