Area Code 85 – Mobile Network
The phone area code for Mobile Network is 85 (international format +8485). Browse local exchange codes (NXX) and carrier assignments below.
Overview of Vietnam's +84 85 Mobile Prefix
The +84 85 prefix is a non-geographic mobile network code assigned within Vietnam's national numbering plan, as administered under the ITU-T E.164 standard. Unlike geographic area codes tied to specific provinces or cities, the 85 prefix is allocated to mobile services, enabling subscribers to be reached anywhere in the country without a fixed location. This prefix is utilized by mobile network operators (MNOs) and mobile virtual network operators (MVNOs) that have secured numbering resources from the Vietnamese Ministry of Information and Communications (MIC).
Technical Formatting and Dialing Procedures
Vietnamese mobile numbers using the 85 prefix follow the national significant number (NSN) format of 9 digits after the country code. Thus, a complete international dialing sequence is +84 85 XXX XXXX (where X represents the subscriber's unique digits). Domestically, callers must dial 0 85 XXX XXXX, with the leading trunk prefix '0' used for national calls. When dialing from abroad, the trunk prefix is omitted, and the country code +84 is used instead.
For example, a local caller in Ho Chi Minh City wishing to reach a subscriber with the number 85 123 4567 would dial 085 123 4567. An international caller from the United States would dial +84 85 123 4567. It is crucial to note that the 85 prefix is not tied to any geographic region; therefore, the subscriber could be located anywhere in Vietnam, and the number does not indicate a specific city or province.
Number Portability and Routing Considerations
Vietnam implemented mobile number portability (MNP) in 2018, allowing subscribers to retain their numbers when switching operators. Consequently, a number beginning with 85 may no longer be associated with its original operator. For routing purposes, the network uses a central database to determine the current operator of a ported number, ensuring that calls and SMS messages are correctly delivered. This does not affect the dialing format but is an important consideration for businesses and individuals relying on the prefix for operator identification.
International SMS and Voice Services
For international SMS delivery, the message should be addressed to +84 85 XXX XXXX. Voice calls from abroad follow the same international format. The 85 prefix is fully integrated into Vietnam's PSTN and VoIP networks, enabling seamless interconnection between mobile and fixed-line services. Callers should be aware that international tariffs apply when dialing Vietnamese mobile numbers from overseas, and these rates vary by service provider.
Regulatory and Commercial Context
The 85 prefix is part of a broader set of mobile codes (e.g., 86, 88, 89, 90, 91, etc.) that were introduced to accommodate the growing demand for mobile services. The MIC periodically reviews and allocates numbering resources to ensure efficient utilization. For businesses, understanding the non-geographic nature of the 85 prefix is essential for customer communication strategies, as it allows for nationwide reach without the need for multiple geographic numbers.