If the SIM card is two-way locked, users cannot make or receive phone calls andmessages.
Nguyen Phong Nha, deputy head of the Vietnam Telecommunications Authority, saidthat 1.67 million subscribers with unverified information have been one-sidelocked 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 informationverified 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 numberswithdrawn on May 15.
Mobile users are advised to follow the verification request to avoid beinglocked. Subscribers can text 'TTTB' to number 1414 without fees to know if thesubscription is verified or not.
Vietnam has about 126 million mobile subscribers./.
