Is a code used in the United Kingdom and Ireland to route Transfers between Financial Institutions. It consists of six digits, it is formatted as three pairs of digits (e.g. 12-34-56) the first two digits are identifying the Financial Institution and the remaining four the branch. Sort Codes are encoded into IBAN but do not appear in BIC.
Sort Code works by helping to identify the participants in the Payment System and properly routing the Transaction. They identify the Financial Institution in question and are adding one more layer of security for correct execution of the Transaction.