Deputy head of the Vietnam Telecommunications Authority Nguyen Phong Nha said such phone numbers have already begun receiving notifications of the plan.
Telecom providers are warning unverified mobile phone number users with at least one text message a day for at least five days. The messages request that users update their personal data, according to Nha.
If the registered personal information is not updated and verified after 15 days, the numbers will not be able to make outgoing calls or text messages. If the data is still not updated another 15 days after that, the numbers will not be able to receive calls or messages. If the data is then not yet updated another 30 days after that, the numbers' contracts will be terminated.
Nha said the final date for telecom providers to notify misregistered users will be Wednesday, March 15.
Then the one-way locking of still unverified phone numbers will begin after March 31, he added.
Vietnam currently has 127 million mobile phone numbers in use, 96% of which belong to either Vinaphone, Viettel or MobiFone, according to the Authority. Representatives from each of these telecom providers said they each have over a million mobile phone numbers linked to faulty data.
A Vinaphone representative said users can update their information either through apps, websites or in person at Vinaphone locations. Personal data and documents not yet available in the national database will need to be manually verified in person at a physical location.
A Viettel representative said getting everyone to register their phone numbers with their correct personal information will be a challenge. The provider has already sent text messages to such numbers asking them to update their information, but very few have responded, the representative added.
The phone number verification process is one of many steps mapped out by a government project on national database development and digitization. Among many goals, the project aims to foster social stability and prevent the inappropriate use of SIM cards.