Errors I’ve rectified in VAT (9)
I believe the answer is:
reservoir
'vat' is the definition.
(thesaurus)
'errors i've rectified' is the wordplay.
'rectified' indicates anagramming the letters.
'errors'+'ive'='errorsive'
'errorsive' with letters rearranged gives 'RESERVOIR'.
'in' is the link.
(Other definitions for reservoir that I've seen before include "Store for water etc" , "Lake for collecting and storing water" , "Area flooded" , "Area for storage, of water say" , "depot" .)