Yes, China is a foreign exchange control country. You need to go through the necessary procedures to remit money abroad. If you go through all the formalities, both BOC and ICBC can remit money to accounts in Hong Kong. Bank of China and Industrial and Commercial Bank of China have branches in Hongkong. The handling fee is one thousandth, plus the cable fee 100 or 150 yuan (if telegraphic transfer is used). There is usually some discount for remittance by Hong Kong. You can check the bank's website. In fact, Bank of Communications and China Merchants Bank also have branches in Hong Kong.