what is the maximum length of phone number
Telephone numbering plan The International Telecommunication Union (ITU) has established a comprehensive numbering plan, designated E.164, for uniform interoperability of the networks of its member state or regional administrations. It is an open numbering plan, however, imposing a maximum length of 15 digits to telephone numbers. The standard defines a country calling code (country code) for each state or region which is prefixed to each national numbering plan telephone number for international destination routing.
Telephone numbers in Hong Kong Telephone numbers in Hong Kong are mostly eight-digit. Fixed land line numbers start with 2 or 3, Mobile (cellular) phone numbers with 5, 6 or 9, pager numbers with 7 and forwarding service with 8. Since the end of 1989, there have been no area codes within Hong Kong.