The underlying rules for IBANs is that the account-servicing financial institution should issue an IBAN, as there are a number of areas where different IBANs could be generated from the same account and branch numbers that would satisfy the generic IBAN validation rules. The site contains over 500 banks with 26,000 sortcodes.
CHAPS Euro - Details of the branch's participation in CHAPS Euro clearing service
C&CCC - Details of the branch's participation in C&CCC clearing service
Printed information - Details of the branch's requirements for the UK Clearings Directory.