Temettu was a tax introduced by the tanzimat reforms in the later Ottoman Empire. Temettu was a tax on estimated (or presumed) business profits; it was mostly paid by merchants and artisans. An early form of temettu was attempted in 1839 (following a firman of 1838 which announced sweeping tax reforms), but it was impractical without detailed information on business incomes. A comprehensive approach to taxation of business profits in the Ottoman empire - rather than the traditional method of taxing specific outputs or assets - only really became possible after a thorough cadastral survey carried out in 1858–1860, which collected detailed information on the status of businesses throughout the empire. Immediately after this, a new temettu was set at 3%; in 1878 it was raised to 4% of estimat