Believe it's on the cards? (6)
I believe the answer is:
credit
This clue is a double definition.
'believe' is the first definition.
(I know that believe is a more specific form of credit)
'it's on the cards?' is the second definition.
(I've seen this before)
(Other definitions for credit that I've seen before include "In this, you have money in the bank" , "Ascribe" , "Money available for a client to borrow" , "Tick - distinction" , "This bank balance is a plus" .)