In the official dispatch, the Telecommunications Department - Ministry of Information and Communications also requires operators to ensure that they do not affect customers' communications during the transition.
Currently, operators are ready for the number conversion. To make automatic number changes for 11-digit phonebooks stored, users of each network can use network apps like My Mobifone, My Viettel, My VNPT, etc. In particular, Vinaphone also allows customers to of other operators can use My VNPT application to transfer numbers without logging in.
Specific instructions on how to convert 11-digit sim to 10-digit number of operators on each device you can follow in the following articles: