Relaxation in the movement of foreigners into Britain and the origins of the Foreign Protestants Naturalisation Act of 1708 (7 Ann c 5) have been seen to lie in the arrival of religious refugees in England and the unsuitability of existing legislation to accommodate large numbers of foreigners. This paper proposes that trade and commercial interests in the American Colonies promoted the cause of Naturalisation by inciting German migration, causing Parliament to relax access to the domestic labour market, and crucially allow German labour to be trafficked to the Colonies. Reform was dictated by the needs of commerce and colonial enterprise, not just by politicians, courtiers and bureaucrats in London. The passing of the Naturalisation Act (1708) and subsequent General Naturalisation Act (1709) both took advantage of Europan warfare and economic disruction and was a direct response to colonial needs to source continental labour. The Act owed much to colonial Americans like Carolina Governor John Archdale who, like his co-religionist neighbour William Penn, acted in the interest of commerce and the colonial classes, broadening the base of non-Anglican access to the Colonies. Opportunities afforded German migrants in the American Colonies, in particular, grew from this signal legislative change.