The purpose of the duty stamps scheme is to indicate that
duty has been, or will be, paid on the contents of the bottle to
which it is affixed. If a bottle of liquor is seen without a stamp
where it should be bearing one, it will be immediately obvious to
retailers, consumers and HMRC that duty has not been paid on the
product. In other words, the absence of a duty stamp, except in
certain prescribed circumstances, indicates that UK duty has not
been paid on those goods. The lack of a stamp renders the goods
liable to seizure and the person holding them liable, on summary
conviction, to a fine of up to £5000.
However, as in most cases the stamp can be applied at any point up until the goods reach a duty point (including in other countries), the presence of a stamp on a bottle will not necessarily provide confirmation that duty has been paid. The requirement for the relevant retail containers of spirits to bear a duty stamp will, however, provide a substantial hurdle for fraudsters.