If the SIM card is two-way locked, users cannot make or receive phone calls and messages. Nguyen Phong Nha, deputy head of the Vietnam Telecommunications Authority, said that 1.67 million subscribers with unverified information have been one-side locked since the end of last month.
They are not allowed to make phone calls or send text messages. From April 1 to 10, 394,000 mobile phone subscribers had their information verified following the Ministry of Information and Communications plan. There remain about 1.2 million unverified subscribers.
Those with unverified information will have their mobile phone numbers withdrawn on May 15.
Mobile users are advised to follow the verification request to avoid being locked. Subscribers can text 'TTTB' to number 1414 without fees to know if the subscription is verified or not. Vietnam has about 126 million mobile subscribers.
