According to the Observatory of Human Rights I.S. has imposed 13 conditions on the town's believers, including bans on the possession of weapons and the establishment of churches and monasteries.
The extremist group posted photos on social media showing bulldozers destroying the town's fifth-century Saint Eliane Monastery last month.
The tax has echos of similar warnings issued by Islamic State which were posted in mosques and broadcast over loudspeakers after it captured the Iraqi city of Mosul last year.
"We offer [Christians] three choices: Islam; the dhimma contract - involving payment... if they refuse this they will have nothing but the sword," the announcement stated.
