Final, incorrect net value (8)
I believe the answer is:
eventual
'final' is the definition.
(I've seen this before)
'incorrect net value' is the wordplay.
'incorrect' indicates anagramming the letters.
'net'+'value'='netvalue'
'netvalue' with letters rearranged gives 'EVENTUAL'.
(Other definitions for eventual that I've seen before include "Coming at last, ultimate" , "Final - happening as a consequence" , "Happening at the end of a period of time" , "Ultimately resulting" , "Ensuing" .)