The international code used to identify bank accounts in cross-border transactions is the International Bank Account Number, or IBAN.
An IBAN is an alphanumeric identifier designed to make international payments more accurate and easier to process. Its structure varies by country, but it generally includes a country code, check digits, and a domestic account identifier that can contain a bank, branch, and account number.
The system was initially developed for payments within Europe and became an international standard, ISO 13616, in 1997. The current standard is ISO 13616:2020. Participating countries use national formats, so IBAN lengths and internal components differ rather than following one worldwide fixed pattern.
A common mix-up is confusing IBAN with BIC or SWIFT. IBAN identifies the recipient’s account, while a BIC—often called a SWIFT code—identifies a bank or financial institution. A routing number is primarily a domestic U.S. banking identifier, so it is not the general international account code described by the question.