Release without payment (4)
I believe the answer is:
free
This clue is a double definition.
'release' is the first definition.
(I know that release can be written as free)
'without payment' is the second definition.
(free of charge)
(Other definitions for free that I've seen before include "Not incurring charge" , "Liberated" , "unemployed" , "On the house" , "Gratis, for nothing" .)