The Isle of Man (Customs) Act 1887 empowered Tynwald with the power to alter the rates of customs duties with temporary effect, subject to confirmation by the annual Acts of Parliament. The Isle of Man (Customs) Act 1955 substituted confirmation by Order in Council, thereby ending the requirement for these Acts to be passed annually. The Isle of Man Act 1958 finally gave the island's insular legislature, Tynwald, the power to pass laws to impose such duties without requiring any confirmation.
^Highmore, Sir Nathaniel Joseph (1907), The customs laws: including the Customs Consolidation Act, 1876, with the enactments amending and extending that act : and the present customs tariff for Great Britain and Ireland : also the customs laws and tariff for the Isle of Man : with other enactments affecting the customs, and notes of ... (2 ed.), Published for H.M.S.O. by Stevens and Sons
^Kermode, D. G. (2001), Offshore island politics: the constitutional and political development of the Isle of Man in the twentieth century, Liverpool University Press, p. 142, ISBN978-0-85323-777-8