Settle account, including pound for theatre poster (8)
I believe the answer is:
playbill
'theatre poster' is the definition.
(I've seen this before)
'settle account including pound' is the wordplay.
'settle account' becomes 'paybill'.
'including' indicates putting letters inside.
'pound' becomes 'l'.
'paybill' placed around 'l' is 'PLAYBILL'.
'for' acts as a link.
(Other definitions for playbill that I've seen before include "advertisement for drama" , "Theatrical poster" , "Theatre poster" .)