The bank joins Santander and Barclays among major banks blocking U.K. customers from purchasing crypto on Binance.
The partnership extends Watford's association with crypto-related firms, following its prior sponsorship by Sportsbet.io.
CryptoUK counts firms such as Crypto.com, Ripple, eToro and Fireblocks among its 60-plus members.
The FCA is concerned younger crypto holders will behave "less rationally and more emotionally, egged on by anonymous and unaccountable social media influencers."
The exchange's move reportedly came after Faster Payments ended its agreement with Binance.
The BOE says growing interest in cryptoassets by institutional investors, banks and payments operators is a concern.
The agency is flagging crypto as a "red alert."
Bitstamp has seen customer numbers more than double since the FCA said Binance Markets should not be operating in the U.K.
The study by behavioral finance firm Oxford Risk concludes 21% of investors rate their knowledge of crypto assets as "poor or non-existent."
The exchange has faced increasing headwinds in Europe over the past two weeks.
The bank is monitoring cryptocurrency activity and placing extra safeguards on certain activities.
The bank has seen a "high level" of crypto investment scams, a company spokesman said.
The number of companies abandoning their bids to register with the financial watchdog has increased by a quarter in less than a month.
The biggest crypto exchanges have grown by working around national regulators. Regulators are starting to take notice.
The seizure was made based on intel regarding the transfer of criminal assets, a statement from the police read.