Money transfer system via banks (4)
I believe the answer is:
giro
'money transfer system via banks' is the definition.
(payment between banks initiated by payer)
This is the entire clue.
(Other definitions for giro that I've seen before include "dish from Greece" , "Credit transfer; sounds like stable spinning wheel" , "System for monetary transfers used for unemployment benefit etc" , "Banking system" , "Cheque" .)