 In 1684 he was appointed Commissioner for tin coinage 1684 until 1687, and Cashier of hearth-tax at a salary of £400 p.a.in return for a £50,000 loan to the King at five per cent interest, holding the post until November 1688.When James II fled the country in 1688, Duncombe refused him a loan of £1,500 to aid his escape.