Before leaving France:
- check that your smartphone is unlocked;
- check its eSIM compatibility;
- keep your French number;
- check your operator's roaming rates;
- back up your phone;
- enable location and anti-theft protection;
- check your account recovery methods;
- optionally download an arrival eSIM.
Once in Vietnam:
- obtain a Vietnamese number registered in your name;
- install your operator's official app;
- choose a plan suitable for your usage;
- install Zalo;
- gradually associate your permanent number with your local services;
- check if Internet is included in your accommodation;
- otherwise, compare FPT, Viettel, and VNPT;
- keep your mobile connection as a backup solution.