The British financial regulator has fined crypto exchange Coinbase $4.5 million for “repeatedly breaching” a requirement that prevented it from serving “high-risk customers.”

American cryptocurrency exchange Coinbase has been hit with a £3.5 million (around $4.5 million) fine as the company “repeatedly” broke a requirement that prevented it from offering services to “high-risk customers,” the Financial Conduct Authority said in a press release.

According to the regulator, CB Payments Limited, being part of the Coinbase Group, operates as a gateway for customers to trade crypto “via other entities within the Coinbase Group.” Despite entering a voluntary agreement with the FCA to restrict onboarding new customers classified as high-risk, CBPL breached it by onboarding and serving over 13,400 high-risk customers. The FCA estimates that more than 30% of these customers deposited nearly $25 million.

“These funds were used to make withdrawals and execute crypto transactions via other Coinbase entities, totaling approximately $226 million.”

The FCA

The British regulator attributed the breaches to CBPL’s “lack of due skill, care and diligence in the design, testing, implementation and monitoring of the controls,” adding that Coinbase’s “inadequacies” in the initial monitoring of compliance went undiscovered for “almost two years.”

As of press time, Coinbase made no public statements on the matter, though the FCA noted that the exchange agreed to resolve the issue and qualified for a 30% discount on its fine. Following the news, Coinbase shares plunged nearly 5%, according to data from Google Finance.