When it is impossible to provide the explanation materials of close relatives' relationship, a letter of commitment from close relatives can be used instead. Article 61 of the Notice of the State Administration of Foreign Exchange on Printing and Distributing stipulates that individuals may entrust their close relatives to handle the settlement and purchase of foreign exchange within the annual facilitation quota on their behalf. At the time of handling, the valid identity documents, power of attorney and close relatives' relationship explanation materials of the trustor and the trustee shall be provided. Individuals can entrust others (including close relatives) to handle the settlement and purchase of foreign exchange, without occupying the annual facilitation quota. The valid identity documents, power of attorney and transaction amount of the trustor and the trustee shall be provided when handling. Close relatives as mentioned in these Guidelines refer to spouses, parents, children, brothers and sisters, grandparents, grandparents, grandchildren and grandchildren. Explanatory materials for close relatives include household registration book, marriage certificate and birth certificate. If it is really impossible to provide explanatory materials for close relatives, it can be replaced by a letter of commitment from close relatives.