IBAN Validator: Verify & Bulk-Check Bank IBANs

Validate IBANs against the official ISO 13616 standard — check digits, country structure and SEPA membership — entirely offline. No bank API, no third-party lookup, and no account data leaves the run. Paste one IBAN or a whole supplier column and get a typed verdict for each.

1. Why use IBAN Validator

A mistyped IBAN is expensive in a way that is easy to underestimate. The payment does not silently disappear — it is rejected days later, someone has to work out why, the supplier chases, and the run is repeated. Occasionally a transposed digit produces a structurally valid IBAN belonging to somebody else, and recovery becomes a bank process rather than a correction.

The check that prevents this is arithmetic. ISO 13616 defines a mod-97 checksum precisely so that single-digit typos and transpositions fail before the payment is ever submitted. What it needs is applying consistently to every row — which is the part that gets skipped under deadline.

This Actor applies it to the whole list, and tells you which check failed rather than returning a bare "invalid".

2. Key features

• Fully offline. Validation is pure arithmetic against a bundled country registry. No bank API, no external service, no rate limit.
• Six typed outcomes, not a boolean — the fix for a wrong country code is different from the fix for a failed checksum.
• Independent structure and checksum results. Both are computed separately, so you can see an IBAN that is the right shape but has a bad check digit.
• SEPA membership flag, kept distinct from "has an IBAN format" — genuinely different questions.
• Both ISO formats returned: electronic (no spaces) for systems, print (grouped in fours) for humans.
• Messy input tolerated. Spaces, lower case and punctuation are normalised before validation.
• Bulk validation of a whole column in one run.
• Nothing stored, nothing transmitted.

3. Who it's for

For finance teams. Before a month-end SEPA payment run, paste in the supplier IBAN column and get a per-row pass/fail with the reason, so a transposed digit is caught before the bank rejects the batch.

For accounts payable and operations. Validate new supplier bank details at onboarding rather than at first payment, so the correction conversation happens while you still have the supplier's attention.

For compliance and KYB. Confirm a counterparty's stated IBAN is structurally genuine and note whether the country is a SEPA participant, as one input to an onboarding file.

For developers and AI agents. Call it inline in a vendor-onboarding flow: submit the IBAN, branch on status, and return the specific failure to the user's form rather than a generic "invalid".

4. How to use it

1. Open the Actor and click Try for free.
2. Paste your IBANs into the IBANs field, one per line. Spaces and lower case are fine.
3. Click Start.
4. Open the Output tab. Filter on valid to isolate failures, or on status to group them by cause.
5. Export as JSON, CSV or Excel.

5. Input parameters

Field	Type	Required	Description
ibans	array of strings	Yes	IBANs to validate, one per entry. Spaces, punctuation and lower case are normalised automatically.

6. Output

{
  "input": "IE29 AIBK 9311 5212 3456 78",
  "valid": true,
  "countryCode": "IE",
  "checkDigits": "29",
  "structureValid": true,
  "checkDigitsValid": true,
  "sepaCountry": true,
  "electronicFormat": "IE29AIBK93115212345678",
  "printFormat": "IE29 AIBK 9311 5212 3456 78",
  "status": "VALID"
}

Every submitted IBAN produces exactly one result, in order.

7. Output fields

Field	Meaning
input	The IBAN exactly as you supplied it.
valid	true only when every check passed.
countryCode	The two-letter prefix, or null if it could not be parsed.
checkDigits	The two check digits following the country code.
structureValid	Whether the BBAN matches that country's official pattern. Computed independently of the checksum.
checkDigitsValid	Whether the mod-97 checksum passes. Computed independently of the structure.
sepaCountry	Whether the country participates in the SEPA scheme. Distinct from whether it uses IBANs at all.
electronicFormat	Normalised, uppercase, no spaces — the form to store and transmit.
printFormat	Grouped in blocks of four — the form to show a human.
status	The precise outcome. See below.

Status values

Statuses are evaluated in precedence order, and the first failure is the one reported:

Status	Meaning	Typical fix
VALID	Every check passed.	—
INVALID_INPUT	Could not be parsed as an IBAN at all.	The field is empty or holds something else.
INVALID_COUNTRY	The two-letter prefix is not a known IBAN country.	Usually a typo in the first two characters.
INVALID_LENGTH	Wrong total length for that country.	A missing or duplicated character.
INVALID_STRUCTURE	Right length, but the BBAN does not match the country's pattern.	Letters and digits in the wrong positions.
INVALID_CHECKSUM	Correct shape, failing mod-97.	Almost always a single transposed or mistyped digit.

INVALID_CHECKSUM is the one worth routing to a human: the IBAN looks right, so it is usually one character away from correct.

8. How it works

Each input is normalised — whitespace and punctuation removed, characters uppercased. The first two characters are looked up in a bundled registry covering roughly 76 IBAN-using countries, which supplies the expected total length, the BBAN pattern and SEPA membership.

Length is checked, then the BBAN pattern, then the ISO 13616 mod-97 checksum: the first four characters move to the end, letters convert to digits, and the resulting number must leave a remainder of 1 when divided by 97. Structure and checksum are evaluated independently so both results can be reported.

No network call is made at any point.

9. API & MCP usage

cURL

curl -X POST "https://api.apify.com/v2/acts/apifmcpfactory~iban-validator/run-sync-get-dataset-items?token=YOUR_APIFY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"ibans":["IE29AIBK93115212345678","DE89370400440532013000"]}'

As an Apify MCP tool. This Actor is callable directly by AI agents such as Claude and Cursor. Usage bills through your own Apify account.

https://mcp.apify.com?tools=apifmcpfactory/iban-validator

Claude Desktop (claude_desktop_config.json):

{
    "mcpServers": {
        "iban-validator": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "https://mcp.apify.com?tools=apifmcpfactory/iban-validator",
                "--header",
                "Authorization: Bearer YOUR_APIFY_TOKEN"
            ]
        }
    }
}

As a standalone MCP server. The same validation also runs as a dedicated hosted MCP server, with validate_iban for a single IBAN and bulk_check_iban for up to 1,000. See the product page for that endpoint.

10. Pricing

$0.005 per IBAN validated, billed per IBAN written to the dataset.

A 1,000-row supplier list costs $5.00 — materially less than one rejected payment costs to investigate.

11. Limits & performance

Memory	256 MB
Network calls	None
Country coverage	Roughly 76 IBAN-using countries
Throughput	Bounded by list size only; validation is arithmetic

12. Limitations

• Structural validity is not account existence. A VALID result means the IBAN is correctly formed for its country. It does not confirm the account is open, or that it belongs to the person you intend to pay. No offline check can establish that.
• No bank name or branch lookup. The bundled registry holds country structure rules, not institution directories.
• Registry coverage is finite. Countries outside the bundled registry return INVALID_COUNTRY, which means "not in our registry" rather than "not a real country".
• SEPA flag is scheme membership, not a statement about any particular payment's eligibility.
• No name-matching. Confirmation-of-Payee style checks require the bank's own service and are out of scope.

13. FAQ

Does this connect to a bank or payment provider? No. Validation is entirely offline, against the ISO 13616 standard and a bundled country registry.

Does a VALID result mean the account exists? No. It means the IBAN is correctly formed for its country. Account existence can only be confirmed by the bank.

Can I validate a whole spreadsheet column? Yes. Paste every IBAN into the ibans field; each produces its own result row.

Why does an IBAN show structureValid: true but valid: false? It has the right shape for its country but fails the mod-97 checksum — the classic single-digit typo. Its status will be INVALID_CHECKSUM.

What is the difference between the electronic and print formats? Electronic is the unspaced uppercase form used in systems and payment files. Print is the same IBAN grouped in fours for human reading. Both are returned.

Does it handle IBANs with spaces or lower case? Yes, both are normalised before validation.

What does the SEPA flag tell me? Whether that country participates in the SEPA scheme. Some countries use IBANs without being SEPA participants, which is why the two are reported separately.

Is any of my data stored? No — nothing is transmitted anywhere in the first place.

GDPR & lawful use

IBANs are processed entirely in memory against a bundled, public reference table (the IBAN registry's country structures) — no external API call, nothing stored beyond your own run's dataset, no third-party enrichment.

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— A Howth Technology Factory tool. Official sources, nothing stored.