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 branch address, the registered legal entity behind the BIC (legal name, registered head office and LEI), 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.