The Hong Kong dollar, also HK$ (symbol) and HKD (code), is Hong Kong's official currency. Other places in the Orient such as Macau are its unofficial users. Regulating it and also functioning as Hong Kong's central bank is the Hong Kong Monetary Authority.
Customers can use the Hong Kong dollars to make withdrawals and deposits from and to their accounts on live casinos. If the currency is accepted at casinos, they can use it for funding. If the Hong Kong dollar is their primary currency, they can begin enjoying their online casino games instantly and not worry about currency conversions anymore.