The messenger heard wrong about the money (6)
I believe the answer is:
herald
'the messenger' is the definition.
(herald is a kind of messenger)
'heard wrong about the money' is the wordplay.
'wrong' indicates an anagram.
'about' indicates putting letters inside.
'the money' becomes 'l' (L can mean 'pounds').
'heard' with letters rearranged gives 'herad'.
'herad' placed around 'l' is 'HERALD'.
(Other definitions for herald that I've seen before include "Ceremonial messenger" , "Announce, presage" , "Bringer of news" , "Proclaim the approach of, like archaic messenger" , "One making proclamations - harbinger" .)