The Vietnamese government is considering new rules limiting the amount of pre-paid SIM cards any one person can register with a single provider to three.
A draft circular from the nation's Ministry of Information and Communications also proposes to cap the number of SIMs an enterprise can register at 100, VNSreported.
The planned regulation is aimed at tightening management of pre-paid mobile customers, the news agency said.
Mobile operators including MobiFone and Viettel have objected to the three SIM per provider cap, on the grounds that SIMs are used in a wide range of devices.
But the ministry states that individual customers looking to register more than three SIM cards would be able sign up with another mobile operator.
With Vietnam having six mobile operators - Viettel, VinaPhone, MobiFone, S-Fone, Vietnamobile and Beeline – this would mean a maximum cap of 18 SIMs per person.