Komainu, a crypto custody joint venture of Nomura, Ledger and CoinShares, has successfully registered with the U.K. Financial Conduct Authority.

The company landed on the FCA register on Friday just before the regulator's new promotions rules came into effect over the weekend. The rules require firms to be registered in the U.K. to be able to approve their own ads and convey appropriate risk warnings to users. Not complying with the rules could mean up to two years of imprisonment.

FCA-registered crypto firms are required to comply with the country's anti-money laundering rules. There are 42 firms on the register, but at the beginning of the year, the regulator said it had received 300 applications from firms since it opened the registration regime in 2021.

Some unregistered companies have withdrawn certain services or stopped serving some clients in response to the new ad rules, while others, like Binance, are relying on other companies to approve their ads. Coinbase added risk disclaimers to its website, the firm said in an email to CoinDesk, while OKX announced modifications such as reducing its token offerings in the country.

The FCA didn't waste any time updating its list of unauthorized firms, adding more than 100 firms – including KuCoin and Houbi – to its warning list on Sunday.

Read more: Why Some Crypto Firms Are Suspending Services in the U.K.