Open in advance (7)
I believe the answer is:
upfront
I believe this is a double definition.
'open' is the first definition.
(I've seen this before)
'in advance' is the second definition.
(I've seen this before)
(Other definitions for upfront that I've seen before include "Informally, straightforward or frank" , "Bold, frank (colloq.)" , "(Of payment) in advance" , "Open - paid at start of transaction" , "Honest - paid in advance" .)