Today I’ll teach you how to extract information from Norwegian bank account numbers.

History lesson

The Norwegian account number system was introduced in 1967 for automatic data processing of checks and other documents. Norwegian Bankers’ Association and the Savings Banks Association in Norway decided on using an eleven-digit number for account representation.


Digits of an account number are grouped into three groups, usually with a small distance or a dot between each group. It is not uncommon to leave these out.

Using dots the format looks like this:


Where XXXX indicates the bank register number and identifies both the bank and branch.

YY indicates the account type. Earlier, banks used these digits for identifying account types and it was relatively standardized. As an example, 10 and 19 were used for payroll accounts (peoples current accounts). Nowadays the use is far less standardized, some banks do not use these two digits to identify specific account types. Now, this ain’t the complete truth. From what I have found out, the digits 00 are used for inter banking accounts. This is because the transactions to / from such accounts is part of a special treatment of clearing systems.

ZZZZ indicates the account number itself. In most cases this is the only thing that distinguishes the accounts.

C is a check digit that is calculated on the basis of all 10 previous digits.The calculation is performed by  Mod 11 using 5432765432.