Financial plan: move before end of August (6)
I believe the answer is:
budget
'financial plan' is the definition.
(I've seen this before)
'move before end of august' is the wordplay.
'move' becomes 'budge' (to budge is to move slightly).
'before' says to put letters next to each other.
'end of' says to take the final letters.
The last letter of 'august' is 't'.
'budge'+'t'='BUDGET'
(Other definitions for budget that I've seen before include "Financial plan - inexpensive" , "occasion for speech" , "Chancellor's plan" , "Plan for expenditure and fund allocation" , "Allocate funds" .)