IBAN & SEPA
ISO 3166-1 Alpha-2 Country Code
An ISO 3166-1 alpha-2 country code is a two-letter identifier assigned to every country and dependent territory in the world. Within the banking context, it appears as the first two characters of an IBAN, immediately telling you which country the account belongs to — for example, DE for Germany, FR for France, or GB for the United Kingdom.
The ISO 3166 Maintenance Agency assigns and updates the codes. Each code is exactly two uppercase Latin letters. In an IBAN, the country code determines which BBAN format rules apply — the expected length, the position of the bank code and account number, and whether a branch code is present. Validation software reads the country code first, then selects the correct rule set from the SWIFT IBAN Registry before checking the rest of the number. The same codes are also used in SWIFT/BIC codes, passport numbers, domain names, and countless other international standards.
The country code is the first line of defence in IBAN validation. An unrecognized or mistyped country code means the IBAN cannot be parsed at all — the validator will reject it immediately. Getting this right is also important for compliance, since payment routing, sanctions screening, and regulatory reporting all depend on accurately identifying the beneficiary's country.
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