This study explores how terrorists use financial technologies in their plots. Using a database of 231 US-based Islamic State actors, it analyses how they move money and make purchases, as well as whether the use of technology affects success. Fundamentally, terrorists opt for simplicity; there is little evidence of sophisticated financial plots. Terrorists tend to use the Internet in two ways: to make purchases and to coordinate transactions. Transactions via Money Service Businesses are more likely to be part of successful plots. Finally, the paper discusses factors which explain this simplicity as well as discussing whether this may change moving forward.