According to the new Exit-Entry Administration Law of the People’s Republic of China which became effective on 1st July, the application of visa extension has to be made 7days in advance before the expiration date of visa. For an extension of residence permit, the application has to be made 30 days in advance before the expiration date.
According to the regulation of The Ministry of Public Security, the processing period of Chinese visa has been changed to 7 working days. For a Chinese residence permit, the processing period has been changed to 15 working days. Your attention will be highly appreciated.
Source: Division of Exit-entry Administration of Shenzhen Public Security Bureau