Pub's note on tax returned (6)
I believe the answer is:
tavern
'pub's' is the definition.
(I've seen this before)
'note on tax returned' is the wordplay.
'note' becomes 'n' (abbreviation).
'on' becomes 're' ('on' can be mean 'with reference to').
'tax' becomes 'VAT' (UK Value Added Tax).
'returned' says the letters should be written backwards.
'n'+'re'+'vat'='nrevat'
'nrevat' in reverse letter order is 'TAVERN'.
(Other definitions for tavern that I've seen before include "Tap-house" , "Building with a bar" , "where drink is available" , "An old inn or hostelry" , "Local" .)