Old three SIM card and ZTE A31 Blade phone

[Noah-1]

I have a PAYG three SIM card for a number of years. I started with a little 3G Blackberry, then moved it to a 4G ZTE A31. I just realized recently that my ZTE cannot receive incoming call and message. I insert an EE SIM card into the phone, it works fine, with VOLTE function on, but for my old Three SIM card, no display for the VOLTE on/off selection. I wonder whether I should have a new SIM card for ZTE A31? Three SIM card works fine too on an iPhone 6S.  

[MichaelP]

Hi there @Noah-1,

Welcome to the Three Community 🙂

The ZTE A31 is definitely VoLTE compatible, but you shouldn't need this to receive text messages, as VoLTE is tied to calling over a 4G connection.

To confirm, is the VoLTE/4G Calling option working on the iPhone 6S with the same SIM?

Have you replaced your SIM card yet, and if so, have you been able to receive calls and texts yet via the ZTE A31?

If not, please try to reset your network settings on the device. You can this with the following steps:

1. Open the Settings app.
2. Tap on System, then Advanced.
3. Select Reset options.
4. Tap on Reset network settings (this will erase all Wi-Fi, mobile data, and Bluetooth settings).

Thanks,
Michael

[Geluk]

Get one from any 3 store.

[Noah-1]

Thanks. I will do that.