Planner's bill found inside damaged crate (9)
I believe the answer is:
architect
'planner's' is the definition.
(thesaurus)
'bill found inside damaged crate' is the wordplay.
'bill' becomes 'chit' (chit is a kind of bill**).
'found inside' indicates putting letters inside.
'damaged' indicates anagramming the letters.
'crate' is an anagram of 'arect'.
'chit' placed inside 'arect' is 'ARCHITECT'.
(Other definitions for architect that I've seen before include "Designer of buildings" , "Perhaps Scott" , "Author" , "professional" , "Wren perhaps" .)