Vessel tax? (3)
I believe the answer is:
vat
This clue is a double definition.
'vessel' is the first definition.
(I know that vat is a type of vessel)
'tax?' is the second definition.
(UK Value Added Tax)
(Other definitions for vat that I've seen before include "Large barrel" , "subject of 17, 8 [CHANCELLORS STATEMENT]" , "Large vessel for storing liquids and a large tax" , "Large container for liquid" , "Tank for holding liquids" .)