The United States Financial Crimes Enforcement Network (FinCEN) issued an advisory to help financial institutions identify and report suspicious activity related to the financing of the Islamic State of Iraq and Syria (ISIS) and its global affiliates. The guidance describes how ISIS raises and receives funds and provides typologies and red flags to support detection and suspicious activity reporting. The advisory outlines methods used to transfer money between ISIS affiliates and channels through which international sympathizers provide financial support. It also frames the guidance against recent ISIS-linked attacks, including those attributed to ISIS-Khorasan (ISIS-K) and an ISIS-inspired homegrown violent extremist attack in New Orleans, and notes consistency with the National Anti-Money Laundering and Countering the Financing of Terrorism Priorities and Treasury’s 2024 National Terrorist Financing Risk Assessment. The advisory is published as FIN-2025-A001 and is directed at sectors including depository institutions, money services businesses, casinos, insurance, mortgage companies or brokers, the precious metals and jewellery industry, and securities and futures firms.