The UK Financial Conduct Authority (FCA) has placed 143 entities on its warning list.
Notable mentions on this list including cryptocurrency exchanges HTX (formerly known as Huobi) and KuCoin.
Not all crypto asset providers are unauthorised, however.
The FCA's list of registered crypto asset providers includes 42 entities, such as Moonpay, eToro, Revolut, Gemini, and Bitstamp.
Unauthorised by the FCA
Entities featured on this list are categorised as "firms that operate without FCA authorisation."
According to the FCA, engaging with an unauthorised firm carries risks.
Users won't have the protection of the Financial Ombudsman Service or the Financial Services Compensation Scheme (FSCS) if issues arise.
The Financial Ombudsman Service, an independent public body established by Parliament, serves as a mediator for resolving disputes between financial businesses and their customers in a fair and unbiased manner.
On the other hand, the Financial Services Compensation Scheme (FSCS) serves as the UK's deposit insurance and investor compensation scheme.
The FSCS can provide compensation if a firm is unable, or likely to be unable, to meet its obligations to claimants.