Viettel successfully completed the procedures for 67.7 percent of subscribers that transferred from other networks, while sending 74.8 percent of subscribers wishing to move.
Meanwhile, Vinaphone received more than 60,000 new subscribers and let go more than 56,000 others.
At the same time, MobiFone and Vietnamobile failed to reach technical standards as their successful switching ratio was less than 70 percent.
Regarding difficulties in the work, Minister of Information and Communications Nguyen Manh Hung said some mobile service suppliers hesitated to help subscribers in switching networks.
To deal with the problem, from May 1, 2019, the ministry assigned a target of 70 percent in transferring ratio to mobile service suppliers. Inspections will be conducted into firms that fail to reach the goal, he said.
A representative from the Vietnam Telecommunications Authority (VNTA) under the Ministry of Information and Communications said from August 2019, network switching will be processed automatically instead of manually.
Alongside, the target network will be allowed to interfere if subscribers have difficulties with the source network during the process.
Mobile number portability (MNP) services, which allow mobile telephone users to retain their numbers when switching from one mobile network operator to another, were launched on November 16 last year.
The Ministry of Information and Communications set an oriented rate for the service at 60,000 VND (2.5 USD).
So far, about 690,000 out of 881,000 subscribers have successfully changed their network, reaching 79.6 percent.