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 was carried out from 1858 to 1860, which collected detailed information on the status of businesses throughout the empire.
In 1886 the temettu was increased to 5%, and it was also applied to wages and salaries; for most of the Ottoman empire, this was the first real income tax, in the modern sense.
[1] Temettu was paid annually;[3] it was a graduated tax, with the rich liable to pay considerably more than the poor.
This extension of temettu was abolished in 1906[6] but later reinstated at the start of World War I and extended to foreigners in any profession.