2G will be switched off from September 15th: 4G phones may also lose connectivity.
The shutdown of 2G networks doesn't only affect those using 2G phones. Some 4G smartphones may still experience call interruptions if they haven't met the 4G network requirements.
According to the plan, from September 15, 2026, 2G networks will cease broadcasting nationwide, except for some specific areas. However, the actual process of shutting down 2G has been implemented by network operators in stages by region, instead of waiting until this date to do it all at once.
At Viettel, some 2G base stations in areas meeting the conversion criteria have been gradually shut down. Therefore, some customers may be affected by voice service disruptions before September 15th if their devices or subscriptions are not yet ready for the conversion.
Notably, those who may be affected are not limited to people using 2G phones.
Why might 4G phones also be affected?
In fact, some smartphones, even though they display 4G and have normal internet access, still switch to the 2G network to maintain voice connectivity when making or receiving calls. This process happens automatically, so most users are unaware of it.
When 2G coverage is unavailable, these phones need to make calls directly on the 4G network via VoLTE (Voice over LTE) technology. If the device does not support VoLTE, VoLTE is not enabled, or the subscription is not activated, users may still be able to access the internet using 4G but will experience interruptions when making or receiving calls.
In other words, having 4G on your phone doesn't necessarily mean you can make and receive calls normally after 2G is turned off.
The group of users who need to pay more attention are those using older phones, laptops, or devices not officially distributed in Vietnam. With these devices, users should proactively check their 4G calling capabilities before the 2G network is switched off.
Who needs to check the phone?
4G smartphone users don't necessarily need to upgrade their devices. First, check if your phone supports VoLTE and if this feature is enabled.
On many devices, users can go to Settings > Cellular or SIM and cellular networks, then look for options such as VoLTE, VoLTE Calls, 4G Calls, or 4G Voice and Data. The name and location of the feature may vary depending on the manufacturer and software version.
For Viettel customers, to maintain calls on the 4G network, subscribers need to use a 4G/5G SIM card, a device that supports VoLTE, enable this feature on their phone, and activate the corresponding service. Viettel currently offers the HDCall service, which supports VoLTE voice calls, at a cost of 0 VND.
If you are unable to make calls on a 4G network, you should check three things: whether your phone supports VoLTE, whether your SIM is a 4G/5G SIM, and whether your subscription has activated 4G voice services.
If the SIM card is incompatible, customers can visit a service center for assistance in exchanging the SIM card. If the phone is not compatible, users need to switch to a 4G/5G device that is capable of making calls on the 4G network.
Viettel always has policies in place to support affected customers.
During the transition and gradual shutdown of the 2G network, Viettel consistently maintained support policies for affected customers, while proactively reviewing, notifying, and guiding subscribers who needed to switch.
Customers can visit Viettel stores, sales points, or support centers to have their devices, SIM cards, and 4G network calling capabilities checked. Depending on the case, customers may be assisted with SIM card replacement and access to appropriate device support programs to maintain communication.
Viettel advises customers to proactively check their network status early instead of waiting until close to September 15th. Because the 2G shutdown is being implemented in stages, in some areas, 2G coverage may be reduced or discontinued before the entire network is completely shut down.
The discontinuation of 2G technology frees up frequency resources for next-generation mobile technologies, improves infrastructure utilization and service quality, and accelerates the user migration to 4G/5G.
Before the 2G network is shut down, users should proactively check their phones, SIM cards, and calling capabilities on the 4G network to ensure uninterrupted communication.
