Customs administration operated under the Lords of Man before the Crown acquired the Island in 1765.

Before Revestment, the Manx customs system belonged to the lordly administration rather than to the British customs service. Duties on goods entering and leaving the Island formed an important part of the Lord’s revenue, and customs officers operated at Manx ports under local authority.

The system sat at the centre of the eighteenth-century running trade. Goods could be imported into Mann under Manx duties which were substantially lower than those imposed in Britain and Ireland. Tea, tobacco, spirits, wine, silk and other goods were then sold to merchants and smugglers who carried them across the surrounding seas.

British officials increasingly treated the Manx customs structure as a major weakness in imperial revenue enforcement. Parliamentary reports on customs fraud repeatedly referred to tobacco being re-landed or smuggled through Mann, while Whitehaven merchants complained that Manx tobacco manufacture and re-export damaged their lawful trade.

The local administration nevertheless remained a functioning revenue system in its own right. Manx officials collected the Lord’s duties, kept accounts and enforced the Island’s own customs legislation. The distinction between this lawful Manx system and the illicit landing of goods elsewhere was fundamental to the disputes surrounding the running trade.

The 1765 purchase transferred the lordly customs revenues and administrative authority to the Crown. The existing Manx arrangement was then replaced by a Crown customs establishment operating under British authority.