The FCA has expressed concern that a "significantly high number" of crypto-asset businesses are not meeting its standards on AML.
Any breaches of the order would face "severe regulatory sanctions," the central bank warned.
Cryptocurrency exchange Binance said a new South Korean law going into effect early next year was another factor.
The company, with operations in Hong Kong, the Philippines, Indonesia and Vietnam, will be permanently shuttering its doors on March 4.
This year, around nine bitcoin firms went belly up for a host of reasons. We take a look at what happened.
European cryptocurrency exchange Yacuna has announced it will close next month.