The so-called Islamic State has often been described as the richest terrorist organization in the world.
This estimate of Islamic State revenues for the years 2014–2016 results from a collaboration between EY and the International Centre for the Study of Radicalisation (ICSR), King’s College London. It is based on a systematic review of open source information about the finances of Islamic State in its core territory in Syria and Iraq.
Estimates vary widely. It remains impossible to say exactly how much money Islamic State has at its disposal.
The group’s most significant sources of revenue are closely tied to its territory. They are: (1) taxes and fees; (2) oil; and (3) looting, confiscations, and fines. We have found no hard evidence that foreign donations continue to be significant. Similarly, revenues from the sale of antiquities and kidnap for ransom, while difficult to quantify, are unlikely to have been major sources of income.
In the years since 2014, Islamic State’s annual revenue has more than halved: from up to $1.9b in 2014 to a maximum of $870m in 2016. There are no signs yet that the group has created significant new funding streams that would make up for recent losses. With current trends continuing, the Islamic State’s “business model” will soon fail.
Heibner, Stefan, Peter R. Neumann, John Holland-McCowan, and Rajan Basra. 2017. "Caliphate in Decline: An Estimate of Islamic State's Financial Fortunes." The International Centre for the Study of Radicalisation and Political Violence (March). https://pdfs.semanticscholar.org/ea21/0ac919dcd374d432001fcf781bb57edf1468.pdf