In 1678 Davenant was appointed Commissioner of the Excise, earning £500 per year (); taxes were collected using the "farming system". In 1683 when Britain ended the tax farming system, Davenant received £1000 per year as Commissioner. In 1685 he was elected to Parliament as M.P. for St Ives. However, the revolution of 1688 saw James II exiled to France and William of Orange installed as king by Parliament. In 1689 Davenant lost his position as Commissioner of the Excise, and his loan to James II was nullified.