national identification number CPR-nummer Danish Personal Identification Number https://en.wikipedia.org/wiki/Personal_identification_number_(Denmark) https://www.wikidata.org/wiki/Q366795 A national identification number, which is part of the personal information stored in the Civil Registration System. The register was established in 1968 by combining information from all the municipal civil registers of Denmark into one. The register came into force by royal assent in Greenland with the effect from 1 July 1972. The number consists of 10 digits, the first six of which indicate the person's birthday, beginning with the date of birth, then the month of birth and finally the year of birth without indicating the century. The last four digits are a serial number, of which he first digit in connection with the year of birth indicates the century in which the person was born. The last digit is even for women and odd for men.