What is bank key?

A bank key is a unique identifier that is used to identify a bank in international banking transactions. It is a code that is assigned by the Society for Worldwide Interbank Financial Telecommunication (SWIFT) to each financial institution that participates in the international payment network. The bank key is a combination of alphanumeric characters that enable communication between banks during financial transactions. The bank key is critical for ensuring that payments are directed to the correct bank and bank account. All banks that participate in international financial transactions must have a unique bank key assigned to them by SWIFT.