With the exception of mail from Mainland China, postal codes are not used in Hong Kong as the Hongkong Post deems it unnecessary to adopt such system. The People's Republic of China's national postal service, China Post, has allocated postal code 999077 to Hong Kong, although this is only sporadically used when sending mail from Mainland China. As China Post does not serve Hong Kong, this code is generally not used in any other scenarios and remains little-known.