In Hong Kong, the legal person of a company is the chairman of the company, that is, the external signatory. If there is any change, its qualification documents need to be notarized before it can be recognized in China. Generally speaking, the supporting document D2A, that is, the Notice of Change of Directors, needs to be notarized by a Hong Kong lawyer, stamped and sent to China Legal Service (Hong Kong) Co., Ltd. for transmission. Only in this way can it be effectively used in China.