How to find the BIC from an IBAN (manually and via API)

Method 1 — read the national registry yourself

Each country’s central bank or banking association publishes its own mapping between domestic bank codes and BICs. For one-off lookups this works; for anything recurring it becomes a maintenance burden, because each source has a different format and update cadence.

Method 2 — ask the counterparty

Reliable when you have one supplier to onboard; useless when you process thousands of payouts, imports or sign-ups. People mistype BICs far more often than IBANs, because the BIC has no checksum — nothing catches a typo before the payment fails.

Method 3 — resolve it with an API

A conversion API keeps the registries so you don’t have to. iban2bic validates the IBAN locally (structure + mod-97), then resolves the bank code against multiple upstream sources with automatic failover, and returns a typed JSON payload: BIC, bank name, full address, and the four SEPA reachability flags (SCT, SCT Inst, SDD Core, SDD B2B).

Pricing is per successful answer: €0.009 for each HTTP 200, and nothing for invalid, not-found or errored lookups. For payment operations that means the failure mode is free.

• One endpoint (POST /v1/convert) instead of 36 national registries.
• Checksums verified before any billable call — malformed input never costs anything.
• Repeat lookups of the same bank resolve from cache in under 100 ms.

Edge cases to plan for

• Fintech and e-money IBANs (Revolut, N26, Wise…) — the BIC may belong to the e-money institution rather than a traditional branch network.
• Virtual IBANs issued for reconciliation map many account numbers to one institution.
• Bank mergers retire BICs: a mapping that was correct last year may now point to an absorbed institution — one reason to resolve at payment time, not from a stale snapshot.