British customs legislation which first gave the Treasury statutory authority to negotiate for the purchase of the Isle of Man and the rights of its Lords.

British customs officials had complained that the low duties charged on goods entering Mann encouraged a large re-export trade. Foreign goods could be imported cheaply into the Island and later landed clandestinely in Britain or Ireland, while British exporters could receive drawback on goods sent to Mann and then re-land them illicitly in Britain.

The Manx legislature attempted to address these complaints in 1711, but the measure was tied to an expectation that Manx produce would be admitted duty-free into Britain. When that concession was not granted, the 1711 Act was suspended by another Act of Tynwald in 1713.

The British response moved beyond customs regulation. Section 25 of 12 Geo. I c.28, An Act for the Improvement of His Majesty’s Revenues of Customs, Excise and Inland Duties, authorised the Treasury to negotiate for the purchase or surrender of rights in the Isle and Lordship of Man.

The provision named James, Earl of Derby, Henrietta Bridget Ashburnham and those claiming through the Derby title. It authorised agreement for the surrender of estates, regalities, powers, honours, superiorities, jurisdictions, rights, privileges, duties, customs, revenues and other advantages connected with the Island.

No purchase followed immediately, but the statutory mechanism remained available. The 1765 Revestment was later carried through under the authority provided by this legislation.