Public surplus before the end of the Budget (5)
I believe the answer is:
overt
'public' is the definition.
(both can mean well-known or unconcealed)
'surplus before the end of the budget' is the wordplay.
'surplus' becomes 'over' (I've seen this before).
'before' is a charade indicator (letters next to each other).
'the end of the' suggests the final letters.
The final letter of 'budget' is 't'.
'over'+'t'='OVERT'
(Other definitions for overt that I've seen before include "totally visible" , "Trove (anag.)" , "Done in an obvious way" , "Voter (anag.)" , "Open, up front" .)