Where VAT requires change of any kind (8)
I believe the answer is:
whatever
'of any kind' is the definition.
(I've seen this before)
'where vat requires change' is the wordplay.
'requires change' indicates an anagram.
'where'+'vat'='wherevat'
'wherevat' with letters rearranged gives 'WHATEVER'.
(Other definitions for whatever that I've seen before include "Of any kind at all" , "Anything; at all" , "Off the wall" , "The waver? (anag)" .)