PRACTICAL GUIDE

IBAN checks: separate a valid format from account verification

By ApiVect · 6 November 2026

Understand supported-country format and checksum checks, submitted-identifier usage, batch limits and the separate subscription before integrating.

An IBAN result needs a precise label. “The format and checksum passed” tells your team something useful about an identifier. “The account is verified” makes a much broader claim. Keeping those statements separate helps developers design clear invoice-import messages and review steps without giving a mathematical check authority it does not have.

This guide explains that boundary for ApiVect’s commercial Payment Identifiers API. It is a practical integration guide, not a new banking standard or evidence of a completed payment.

Start with the question your check answers

Swift, the registration authority for national IBAN formats, explains that ISO 13616 specifies their structure and publishes the IBAN Registry. Different countries have different national formats. That registry is a reference for structure; it should not be confused with an individual account or payee lookup.

ApiVect checks the format and MOD97 checksum for its supported country set: BE, DE, DK, FI, FR, GB, IE, NL, NO and SE. Keep that coverage visible in your application. A country outside the supported set is a coverage boundary, not evidence that its banks or accounts are invalid.

Keep account and payee checks separate

A passing ApiVect result does not verify a bank or account, account existence, ownership, a payee name or national account checkdigits. Payment execution, KYC and a legal-compliance guarantee are outside this product’s scope. Do not replace your existing supplier-change review or payment-provider checks with an IBAN format result.

For an invoice-import interface, use wording such as “IBAN format and checksum passed for a supported country.” Keep the separate approval decision visible. If a supplier sends changed payment details, the formatting result alone cannot establish that the change is authorised.

Budget by submitted identifier

The allowance counts identifiers in completed requests. Invalid values, duplicates and unsupported-country results each use a unit. This differs from treating a whole batch as one check or assuming that repeated values are automatically free.

Synthetic planning example: a completed batch contains 75 submitted identifiers. Twenty have invalid results, and five entries repeat earlier values in the same batch. The completed submission still uses 75 units. Those repeated entries are different from an exact completed retry within the original 24-hour replay window, which adds no usage.

In your own import code, retain local row references so that a finding can be matched to the right record. Decide whether duplicate source rows should be submitted separately before building a request. Do not silently remove rows if doing so would hide a reconciliation issue in your application.

Check both the item and byte limits

A batch supports up to 100 items, and the authenticated JSON body must fit within 16 KiB. Its complete unit requirement must fit the remaining allowance. Counting items alone does not check the encoded body size; measure the final UTF-8 JSON before sending it.

Workspace keys share limits of two requests per second and 60 per minute, with one operation at a time. Coordinate workers across your integration rather than giving each key an independent request budget. These are admission limits, not a promised response time or a customer SLA.

Keep identifiers out of URLs

Send IBAN values only in the authenticated JSON request body. Do not put them in a URL, tracking parameter, screenshot or support example. ApiVect responses contain validation metadata without the full IBAN. Review what your own application logs and retains separately; a bounded API response does not control your client-side logging.

Use the authenticated integration guide for request construction and recovery. A timeout is not proof of either completion or non-completion, so do not invent a fresh request or an assumed billing outcome in response. Follow the documented retry workflow and distinguish it from sending the same value again as a new submission.

Choose the right subscription

Payment Identifiers Starter is a separate subscription: EUR 5 per month excluding VAT for 10,000 submitted identifiers, with a hard allowance and no trial, rollover or overage. It is not part of the current eight-product ApiVect Complete package. Initial admission is limited; check current availability in Billing before planning a purchase.

Review the current IBAN plan and limits, or read the integration guide after signing in.

Sources and further reading

• Swift: national IBAN formats, ISO 13616 and the IBAN Registry.
• ApiVect: current Payment Identifiers scope, usage policy and subscription terms.

Sources checked on 6 November 2026. The planning example is fictional and contains no customer or account data.

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