About 75 million 11-digit subscribers will switch to 10 digits from today.

The conversion of 11-digit subscribers to 10-digit subscribers will be implemented from 0:00 on September 15 with 3 phases. The parallel dialing phase (applying both old and new dialing methods) starts from 0:00 on September 15 to the end of November 14. During this time, calls dialed according to the old or new network code will be successful.

The Ministry of Information and Communications said that with the above changes, the last 7 digits of the 11-digit subscriber number will remain the same, only the network code will change. For example, when wanting to call the 11-digit VinaPhone subscriber number 0123.xxx.xxxx, after changing the network code, the user will dial 083.xxx.xxxx, meaning that only the old network code (123) will be replaced with the new network code (83) when dialing.

In phase 2, from 0:00 on November 15, 2018 to June 30, 2019, calls using the new network code will be processed normally. Calls using the old network code will receive a notification in English and Vietnamese stating that the network code has changed and instructions for dialing using the new network code.

After June 30, 2019, this notice will end, calls will only be successful when users dial according to the new network code.

A report by the Telecommunications Department released in May said that about 60 million 11-digit subscribers and 700 VSAT subscribers will be affected by this plan. However, according to the network operators' reports, this number is over 74.5 million subscribers. Of which, Viettel has 43 million, MobiFone 14 million, VinaPhone 15 million, Viettelmobile 2.5 million.

Previously, the carriers had many months to prepare and said they were ready for the transition.Mr. Nguyen Viet Dung, Deputy General Director of Viettel Telecommunication Corporation (Viettel Telecom), said that this network currently has 43 million active 11-digit subscribers.

"Viettel customers will not have to do anything to switch to the 03 number," Mr. Dung said, adding that the conversion is not just a simple change of subscriber number, but Viettel has nearly 1,000 services (value-added services, switchboard, voice...) that must be converted. Viettel also supports tools for customers to update their contacts after October 7. The entire conversion will be done at night so as not to greatly affect customers.

Meanwhile, MobiFone has 14 million 11-digit subscribers and the change to the new prefix will be implemented in 5 nights, from September 15 to October 2. With about 15 million 11-digit subscribers, VNPT will also carry out the change to the prefix in 5 nights, scattered from September 15 to 27. Each night, there will be from 2.3 to 4.8 million VinaPhone subscribers converted.

With Vietnamobile, 2.5 million subscribers with the prefix 0186 and 0188 of this network will be converted to prefix numbers in 5 nights, from September 15 to 23 with about 400,000 - 500,000 subscribers converted each time. Meanwhile, although the number of subscribers was not announced, Gmobile also said that the conversion will be carried out in 4 nights: September 15, 17, 19 and 21.

Currently, 4 network operators, Viettel, MobiFone, VinaPhone and Vietnamobile, all have the feature to convert contacts on mobile applications from 11 digits to 10 digits. For regular phone users, the network operators will provide maximum support for this group of customers at transaction points.

Previously, to prepare for the network code conversion plan, the State Bank also required banks to develop a conversion plan in accordance with the roadmap of the Ministry of Information and Communications and mobile telecommunications enterprises. In particular, banks proactively develop appropriate conversion plans, taking into account technological and electronic application solutions such as tools for customers to register to change phone number information via website, Internet-Banking, Mobile-Banking, SMS-Banking... to ensure convenience for customers. The State Bank also required banks to ensure safety and continuity of service activities during the implementation process.

11-digit subscribers have been officially granted by the management agency to network operators since 2007. However, up to now, the Ministry of Information and Communications has determined that, according to recent statistics, the efficiency of using 3-digit mobile network codes (starting with 1xx) is much lower than that of 2-digit codes (starting with 9x). In addition, the rate of phone subscribers using 1xx network codes leaving the network is quite high. Spam SIMs, spam messages... also mainly arise from 1xx network codes. Therefore, converting 1xx network codes to new 2-digit network codes not only creates fairness in dialing length for service users but also contributes to limiting the rate of subscribers leaving the network, limiting spam SIMs, spam messages...

The plan to convert and unify mobile subscribers to 10 digits is included in the Telecommunications Numbering Plan set out by the Ministry of Information and Communications in Circular 22, issued in 2015. According to this plan, in 2017, when the re-planning of fixed area codes is completed, the management agency will convert 11-digit mobile subscribers to 10 digits. However, the implementation has only been carried out so far, which is one year later than the original plan.