---
title: Kontosjekker
description: Which bank owns this account number — and is the number even valid?
---

Kontosjekker answers three questions about Norwegian bank accounts:

1. **Which bank owns this account number?** The first four digits of every
   Norwegian account number identify the bank. Kontosjekker maps all 2 300+ of
   those identifiers to their bank and BIC.
2. **Is this account number valid?** MOD-11 for domestic numbers, MOD-97 for
   IBANs, plus conversion between the two.
3. **What does the bank look like?** Logos, content-addressed and cacheable
   forever.

The register comes from the [Bits BIC/IBAN table](https://bits.no/en/iban/),
the authoritative Norwegian source. Every response tells you which publication
it was answered from.

## Try it

```bash
curl https://api.kontosjekker.asamsig.com/v1/accounts/validate \
  -H "content-type: application/json" \
  -d '{"accountNumber": "8601 11 17947"}'
```

```json
{
  "account": {
    "valid": true,
    "bban": "86011117947",
    "formatted": "8601 11 17947",
    "iban": "NO9386011117947",
    "ibanFormatted": "NO93 8601 1117 947",
    "clearingCode": "8601",
    "error": null
  },
  "bank": {
    "bic": "DABANO22",
    "institutionCode": "DABA",
    "name": "Danske Bank",
    "country": "NO",
    "clearingCodes": ["8101", "8102", "…"],
    "logo": {
      "formats": ["png"],
      "hash": "5f2c…",
      "url": "https://api.kontosjekker.asamsig.com/v1/banks/DABANO22/logo.png?v=5f2c…"
    }
  }
}
```

No key is needed to try it — anonymous callers get 60 requests per minute.
See [Authentication](/authentication) to raise that.

## Where to go next

- [Account numbers](/account-numbers) — what the API checks, and what it cannot
- [Authentication](/authentication) — API keys and rate limits
- [Logos](/logos) — serving bank logos
- [React component](/react) — an account input with bank detection built in
- [API reference](/api) — every endpoint, generated from the service itself

## A validity caveat

A valid check digit means the number is *well formed*, not that the account
*exists* or that it belongs to whoever claims it. No public register in Norway
exposes that. Treat validation as a way to catch typos, never as proof of
ownership.