State aid arranged by leaders in head office (5)
I believe the answer is:
idaho
'state' is the definition.
(US state)
'aid arranged by leaders in head office' is the wordplay.
'arranged' indicates anagramming the letters (letters rearranged).
'by' is a charade indicator (letters next to each other).
'leaders in' suggests taking the first letters.
The first letters of 'head office' is 'ho'.
'aid' is an anagram of 'ida'.
'ida'+'ho'='IDAHO'
(Other definitions for idaho that I've seen before include "North-western US state" , "NW state of USA" , "North-western state of America" , "US state E. of Oregon" , "Union member?" .)