Subscribers can text 'TTTB' to number 1414 without fees to know if the subscription is verified or not. — VNA/VNS Photo

Nguyễn Phong Nhã, deputy head of the Vietnam Telecommunications Authority, said not many two-way locked subscribers had verified their information.

So far, just over 154,000 mobile phone subscribers that were two-way locked from April 15 have verified their information, accounting for only about 13.48 per cent of total two-way locked SIM cards.

Around one million unverified SIM cards will likely be withdrawn after May 15.

According to the authorities, mobile phone information verification has received public consensus, and users are aware of the importance of verification.

Once two-way locked, subscribers can not verify information through websites and applications of mobile phone operators. They must visit the offices of mobile phone service providers for verification.

Mobile users are advised to follow the verification request to avoid SIM card withdrawal. Subscribers can text 'TTTB' to number 1414 without fees to know if the subscription is verified. — VNS