How do terrorist organizations get their funding?

Terrorist organizations get funds through several means. For example, ISIS gets most of its funds through taxation. The organization tax the people and business owners within the territory. ISIS charges import taxes, rent for businesses, fines for breaking laws, utility bills and income tax.

Terrorist organizations get funds by requesting for ransom for people they kidnap. Many nations have paid ransoms to these organizations for their citizens to be released.

For terrorist organizations that have access to oil, they export the oil to generate funds.
Many also get funds from supporters that make donations to the organizations. They get access to bank accounts and they scam banks to generate funds.

The oil fields that were captured in Syria and Iraq have been significant funding providers for the terrorist group. Taxation and extortion are another way that they get their funding. They have created a system of blackmail and taxation which generates millions of dollars per year for the terrorist organization. Islamic fighters and their families receive a variety of free services, including housing and medical care, while others are taxed heavily. Kidnapping for ransom also generates millions of dollars.

Wealthy donors also attribute a healthy source of income for terrorists. Wealthy families and other donors in Saudi Arabia, Qatar, Kuwait, and the United Arab Emirates often donate because they fear Iran and Assad. The Islamic State has also seized historical artifacts and antiques as a source of income. The Islamic State gained billions of dollars in cash through state-owned banks. Agriculture, Real Estate, Sales of other looted property and human trafficking also generate income for terrorist organizations.