Is the account number the same as IBAN?

No. IBAN is international and consists of country code + check digits + Norwegian account number, 15 characters total for Norway. Example: `NO93 1503 20 31416`. IBAN is used for international transfers; domestic transfers within Norway just use the 11-digit number.

Does the register number always tell me which bank?

Almost always. The first four digits are assigned to banks by Bits (the banks’ shared infrastructure company). In mergers, a bank can inherit several ranges. Account numbers aren’t auto-migrated, an old Fokus Bank account keeps its register number even after DNB took over.

Can I see what type of account it is (checking, savings)?

The two middle digits (the "account code") in theory indicate the account type, but practice varies widely between banks. Without a bank-specific lookup table you can’t reliably tell whether an account is checking, savings or a housing savings account.

What if the check digit "should" be 10?

The base is skipped, just like with organisation numbers. Banks only assign account numbers where the check digit fits in a single digit (0–9). You’ll never encounter a valid account number whose last digit "should" be 10.

Norwegian Bank Account Number Generator & Validator

How it works

Norwegian account numbers have 11 digits, the last being a MOD11 check digit. Dots may separate the groups (1234.56.78903). The numbers here are valid test data only.

About this tool

A Norwegian bank account number is 11 digits, grouped as `NNNN NN NNNNN`. The first four digits are the register number identifying the bank (e.g. 1503 = DNB, 3625 = SpareBank 1), the next two are the account code (account type), and the last five are the account itself, including a check digit at the end. The check digit is computed with the MOD11 algorithm and weights 5, 4, 3, 2, 7, 6, 5, 4, 3, 2 from the left. This tool validates a Norwegian account number, formats it nicely, and (based on the register number) tells you which bank the account belongs to. Everything runs locally.

How to use it

Paste the account number (with or without spaces/dots) into the input field.
The tool checks that it’s 11 digits and that the check digit is correct.
For a valid number, it shows the bank (derived from the first four digits) and a clean format `NNNN NN NNNNN`.
To compute the check digit: enter the first 10 digits, and the 11th will be shown.
Everything happens locally, account numbers never leave your browser.

Examples

Valid DNB account

Input15032031416

Output1503 20 31416 ✓ (DNB)

Tax account

Input63450603204

Output6345 06 03204 ✓ (Norwegian Tax Administration)

Invalid account number

Input12345678900

Output✗ Wrong check digit

The sequence 12345678900 does not have a valid check digit. All-zero numbers are also invalid.

Common use cases

Validating account numbers in invoicing, payroll or HR software.
Checking employee bank accounts during onboarding before the first payroll run.
Auto-formatting account numbers in prints and exports (`NNNN NN NNNNN`).
Cleaning imported customer registers where account numbers may have typos.
Warning a user who enters a mistyped account number before a transfer.
Distinguishing between bank partners in accounting based on the register number.

Frequently asked questions

Is the account number the same as IBAN?: No. IBAN is international and consists of country code + check digits + Norwegian account number, 15 characters total for Norway. Example: `NO93 1503 20 31416`. IBAN is used for international transfers; domestic transfers within Norway just use the 11-digit number.
Does the register number always tell me which bank?: Almost always. The first four digits are assigned to banks by Bits (the banks’ shared infrastructure company). In mergers, a bank can inherit several ranges. Account numbers aren’t auto-migrated, an old Fokus Bank account keeps its register number even after DNB took over.
Can I see what type of account it is (checking, savings)?: The two middle digits (the "account code") in theory indicate the account type, but practice varies widely between banks. Without a bank-specific lookup table you can’t reliably tell whether an account is checking, savings or a housing savings account.
What if the check digit "should" be 10?: The base is skipped, just like with organisation numbers. Banks only assign account numbers where the check digit fits in a single digit (0–9). You’ll never encounter a valid account number whose last digit "should" be 10.

Technical background

The account number structure is set by Bits AS (formerly BBS). The check digit is computed with MOD11 and weights 5, 4, 3, 2, 7, 6, 5, 4, 3, 2 from the left (same as org numbers, but with two extra leading digits): sum = Σ(digitᵢ × weightᵢ), remainder = sum mod 11, check digit = 11 − remainder. Remainder = 0 → check digit 0; remainder = 1 → "10" not allowed, base is skipped. Norwegian IBAN prepends `NO` + two check digits (computed with the international IBAN algorithm based on mod-97) before the 11 Norwegian digits, 15 characters in total.