British customs legislation of 1720 which attempted to extend anti-smuggling enforcement into the Isle of Man.

The measure later became important during the parliamentary debates over Revestment in 1765. Counsel for the Duke of Atholl described 7 Geo. I as the precedent on which the new bill was being modelled, but argued that its Manx provisions had never been effectively enforced.

The Act treated Mann alongside Jersey and Guernsey and provided for seizures connected with customs offences to be prosecuted either in the Westminster courts or in courts of the place where the offence had occurred. That formula caused difficulty in Mann because the King did not then possess his own courts or customs officers on the Island.

In the 1765 debate the Duke’s counsel cited the opinion of Lord Hardwicke that the Act gave British customs officers no effective power to make seizures within Mann. If goods were seized there under the statute, the proceedings would have had to be carried to the appropriate court in Britain.

Counsel therefore described the 1720 statute, as far as Mann was concerned, as a “dead letter”. He asked whether any customs officer had ever entered the Island under its authority, made a seizure there or prosecuted such a seizure to condemnation, and stated that no such example could be produced.

The 1765 legislation was framed in part as a response to that earlier failure.