The directory is maintained by VocaLink on behalf of UK Payments Administration (formally APACS).
The ISCD contains the sort code, SWIFT Bank Identifier Code (BIC), payment information, clearing information and contact details for all bank branches and sub-branches involved in the UK payment clearing system.
The ISCD is used by organisations to check the validity of sorting codes, which, combined with modulus checking of the bank account number and sorting code, is essential for successful Direct Debit and BACS Credit transactions.
To ensure that organisations have access to accurate information, VocaLink updates the ISCD once a week and makes it available to download.
The Extended Industry Sorting Code Directory (EISCD) is based upon the ISCD and was introduced to provide reference data to support the UK's Faster Payments service.