A: No. A SIM unlock is permanent (code-based or server-based). Factory reset preserves the unlocked status.
Once unlocked, you are no longer tethered to a single network. You can switch to any carrier that offers better coverage in your area or cheaper monthly rates. This is perfect for users who want to take advantage of competitive prepaid plans. Vivo Y12a Unlock Sim
After entering the correct code:
Alternatively, check your device settings: Vivo Y12a Unlock Sim
For older Vivo models, some technicians use a "SIM Unlock Clip" or "Octopus Box." This requires soldering or specialized tools and is unless you are a professional. Vivo Y12a Unlock Sim