Note on VAT returned in pub (6)
I believe the answer is:
tavern
'pub' is the definition.
(I've seen this before)
'note on vat returned' is the wordplay.
'note' becomes 'n' (abbreviation).
'on' becomes 're' ('on' can be mean 'with reference to').
'returned' is a reversal indicator.
'n'+'re'+'vat'='nrevat'
'nrevat' reversed gives 'TAVERN'.
'in' is the link.
(Other definitions for tavern that I've seen before include "Tap-house" , "Old-fashioned word for pub" , "An old English pub" , "An old inn, musically in the town" , "Building with a bar" .)