Open University almost immediately accepting folio (7)
I believe the answer is:
upfront
'open' is the definition.
(I've seen this before)
'university almost immediately accepting folio' is the wordplay.
'university' becomes 'u' (abbreviation for university).
'almost' means to remove the last letter (most of the word but not all of it).
'immediately' becomes 'pronto' (I've seen this before).
'accepting' means one lot of letters goes inside another.
'folio' becomes 'f' (abbreviation listed in Chambers).
'pronto' with its last letter taken off is 'pront'.
'pront' placed around 'f' is 'pfront'.
'u'+'pfront'='UPFRONT'
(Other definitions for upfront that I've seen before include "Straightforward or prominent" , "Informally, straightforward or frank" , "Open - frank - paid out beforehand (of money)" , "(Of payment) in advance" , "Open, honest" .)