Danish CPR number validator

CPR-nummer (personnummer)

Check a Danish CPR number, see which date and century it encodes, and whether it passes the modulus 11 check.

Nothing leaves your browser. The check runs in this page, and its security policy blocks every network request, so what you type is never sent anywhere.

Check a number

How a CPR number is built

Part Example Meaning
Date of birth 070761 DDMMYY
Serial number 4285 The first digit and the year give the century; the last digit is odd for men and even for women

Why a failed modulus 11 check is not an error

Older CPR numbers pass a modulus 11 check. Since 2007, Denmark also issues numbers that do not, because some birth dates ran out of numbers that pass. A validator that rejects every number failing the check rejects real people. This tool shows the result of the check, but only a wrong format or an impossible date makes a number invalid.

Test numbers

There is no test generator here on purpose: Denmark has no reserved range for test numbers, so an invented CPR number can belong to a real person.

Got a whole spreadsheet of these? Scrubsheet finds ID numbers, IBANs, names and emails in Excel and CSV files and anonymizes them, in your browser, without uploading the file.

Anonymize a spreadsheet

More free tools