Financial institutions taking pounds from dummies (5)
I believe the answer is:
banks
'financial institutions' is the definition.
(bank is a kind of financial institution)
'pounds from dummies' is the wordplay.
'pounds' becomes 'l' (L can represent the monetary pound).
'from' suggests deleting specific letters.
'dummies' becomes 'blanks' ('blank' can be a synonym of 'dummy').
'blanks' with 'l' taken away is 'BANKS'.
'taking' is the link.
(Other definitions for banks that I've seen before include "Relies" , "Financial institutions" .)