In the UK, Part 3 of the Terrorism Act 2000 criminalises terrorist financing and makes it an offence to:
use, possess, or raise funds for the purposes of terrorism, or enter into arrangements to provide funds or property for that purpose.
The Anti-Terrorism Crime and Security Act 2001 allows for the seizure of terrorist cash.
Terrorists need money, not only to fund attacks but also to fund the travel, false documents, safe houses, food, bribery, training, and recruitment which a terrorist organisation needs to function.
Terrorist financing provides funds for terrorist activity. It may involve funds raised from legitimate sources, such as personal donations and profits from businesses and charitable organisations, as well as from criminal sources, such as the drug trade, the smuggling of weapons and other goods, fraud, kidnapping and extortion.