Can I compute the BIC from the IBAN mathematically?

No. The IBAN’s check digits are computable, but the bank-code→BIC mapping is registry data maintained by national authorities — it must be looked up, not calculated.

Do IBAN and BIC have to match?

They should be consistent: the BIC must belong to the institution whose bank code appears in the IBAN. Many banks reject payment files where agent BIC and IBAN bank code disagree.

Is a routing number the same as a BIC?

No. Routing numbers (like US ABA numbers or UK sort codes) are domestic identifiers. The BIC is the international identifier; domestic codes often appear inside the IBAN instead.

Guide · 4 min read

IBAN vs BIC: the difference, and when you need each one

Last updated 17 July 2026

IBAN and BIC answer two different questions. The IBAN answers “which account?”; the BIC answers “which bank?”. Payments need the account, routing needs the bank — which is why forms keep asking for both.

Side by side

	IBAN	BIC / SWIFT
Identifies	A specific bank account	A financial institution (or branch)
Standard	ISO 13616	ISO 9362
Length	15–34 chars (fixed per country)	8 or 11 characters
Contains	Country, check digits, bank code, account	Bank, country, location, optional branch
Validated by	mod-97 checksum (offline)	Registry lookup (SWIFT directory)
Example	IT60 X054 2811 1010 0000 0123 456	UNCRITMMXXX

When is the BIC still required?

SEPA regulation introduced the “IBAN-only” rule for consumer payments inside the area, so a typical bank transfer form now needs just the IBAN. But the BIC never disappeared from the plumbing: banks derive it internally to route, and plenty of B2B flows still require it explicitly.

ISO 20022 / pain.001 batch files with mandatory agent (BIC) fields.
Cross-border wires outside SEPA, where correspondent routing needs the institution.
PSPs and marketplaces validating payout destinations before onboarding a seller.
Treasury systems reconciling which institution actually holds a counterparty account.

You have the IBAN — getting the BIC

The BIC is not a substring of the IBAN, but the IBAN’s embedded bank code maps to it. Resolving that mapping requires per-country registry data (Bundesbank BLZ files in Germany, ABI tables in Italy, and so on). A single API call to iban2bic returns the BIC, bank name, address and SEPA scheme reachability for any SEPA IBAN — at €0.009 per successful lookup.