What goes to block army career, perhaps (7,6)
I believe the answer is:
service charge
'what goes to block' is the definition.
(charge given to all residents of a block of flats)
'army career perhaps' is the wordplay.
'army' becomes 'service' (military service).
'career perhaps' becomes 'charge' (career can mean to charge around).
'service'+'charge'='SERVICE CHARGE'
(Other definitions for service charge that I've seen before include "Restaurant bill add-on" , "Restaurant bill addition" , "Additional restaurant fee" , "Part of bill" , "it may mean that extra 10%" .)