Our branch of HSBC in HK required a letter of introduction from our bank in the states. It is helpful to bring a goodwill letter with you when opening an account. We also found it helpful to open an account with HSBC in the US. (We got a credit card). Even though the two banks don't share account information, they value that you are a loyal customer of the bank. Also, the HSBC credit card often has promotional discounts with merchants in HK, and has a very low currency conversion rate making it a good value for overseas travel.