Behind with payments (2,7)
I believe the answer is:
in arrears
'behind with payments' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for in arrears that I've seen before include "Behindhand (with rent)" , "Behind with payments" , "Owing" , "Position when a debt remains unpaid after its due date" , "Late with payments" .)