SWIFT/BIC code structure

A SWIFT/BIC code is 8 or 11 characters and encodes the bank, country, location, and optionally a specific branch:

Part	Length	Example	Meaning
Bank code	4 letters	CITI	Institution identifier
Country code	2 letters	US	ISO 3166-1 alpha-2 country
Location code	2 characters	33	City or regional identifier
Branch code (optional)	3 characters	XXX	Specific branch; XXX = head office

Example: CITIUS33XXX = Citibank (CITI) · United States (US) · New York (33) · head office (XXX).

When SWIFT codes are used

International wire transfers: required to route funds to a foreign bank account.
SEPA payments (within Europe): combined with an IBAN to identify both bank and account.
Correspondent banking: banks use SWIFT codes to communicate and settle interbank transactions.

SWIFT codes identify banks, not individual accounts. An IBAN is required to specify the account itself.

These two identifiers serve different purposes and are both typically required for international transfers to European bank accounts:

IBAN (International Bank Account Number): identifies a specific bank account. Up to 34 alphanumeric characters, structured by country.
SWIFT/BIC (Business Identifier Code): identifies the bank holding that account. 8 or 11 characters.

US banks do not use IBANs. For US wire transfers, the routing number (ABA number) plays a similar role to the IBAN.

Error	Cause
Wrong length	Only 8 and 11 characters are valid; 9, 10, or other lengths are not
Invalid country code	Characters 5–6 must be a valid ISO 3166-1 alpha-2 code
Lowercase characters	BIC codes must be uppercase; lowercase inputs indicate a formatting error
Invalid characters	Only letters and digits are allowed; spaces, hyphens, and special characters are invalid