IBAN validation API
Mod-97 fits in fifteen lines — the per-country length table does not, and a Maltese IBAN is 31 characters where a Norwegian one is 15. The API returns the verdict and the breakdown.
The call
One endpoint for all four types. The key is generated in your dashboard and shown once.
curl -X POST https://data-checker.fr/api/v1/validate \
-H "Authorization: Bearer dck_live_…" \
-H "Content-Type: application/json" \
-d '{"type":"iban","value":"DE89370400440532013000"}'What the verdict covers
Mod-97 check digits
ISO 7064 mod-97-10: the first four characters move to the end, letters become numbers, and the resulting integer must be congruent to 1 modulo 97. This catches every single-character error and nearly every transposition.
The country's expected length
Every country has one fixed length, checked before any arithmetic. It is the table nobody wants to maintain in their own code, and it changes whenever a country joins the register.
SEPA membership
The sepa flag says whether the country is inside the single payments area — which is not the same as the European Union: Switzerland and the United Kingdom are in it.
BBAN breakdown
The response returns the country's BBAN structure, and for French IBANs the bank / branch / account split with the national RIB key check.
A valid IBAN is not an open account
The check digits prove the number is consistent with itself. They do not say the account exists, is open, or whose name is on it. Only the receiving bank knows — and under SEPA the transfer executes on the IBAN alone: in most countries the account name is not checked.
That gap is exactly what invoice fraud exploits: a plausible IBAN in a modified invoice passes every format check on the way. For a new supplier, confirm the details through a channel other than the one that delivered the invoice.
Credits, not a subscription
One credit is one verification, whatever the type. You pay once, credits never expire, and nothing renews on its own.
Starter
9 €
1,000 verifications
0,009 € per verification
Growth
49 €
10,000 verifications
0,0049 € per verification
Scale
149 €
50,000 verifications
0,003 € per verification
Frequently asked questions
Does the API check that the account exists?
No, and no offline check can. Existence checks run through banking confirmation-of-payee services, which are paid and restricted to institutions. The API validates form, check digits and structure — which removes typos, that is, the large majority of failed transfers.
How many countries are covered?
The 27 member states, plus the wider SEPA area — Switzerland, the United Kingdom, Norway, Monaco, Andorra, San Marino, Liechtenstein, Iceland — and the other countries in the ISO 13616 register.
What does one verification cost?
One credit, like every other type. From €0.003 each on the largest pack, with no subscription and no expiry.
Try it without a key first
The same check, in your browser, free and without an account — enough to confirm the verdict matches what you expect.
IBAN validator