Cash in, as coupons (6)
I believe the answer is:
redeem
'cash in as coupons' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for redeem that I've seen before include "exhange for cash?" , "Ransom" , "Buy black, or convert into cash" , "Exchange (coupon) for cash or goods" , "Save, perhaps from pawn" .)