I've just bought a new mobile phone (Galaxy A40) and a smaller SIM that fits it from O2 (O2 SIM only contract).
I've got everything transferred to the new phone. All works fine incl. internet but when I try to make a call I get a 'Not registered on network report'.
Of course, under the present status I can't seem to get any info. from O2.
Any help gratefully received.
Laurie

Laurie,

This type of thing can happen following Operating System upgrades on the handset.
Try going to settings (that's the gear cog icon) then Connections, then Mobile Networks. Now you want to select something that will be something like, Network Operators or Available Networks. Once there you should manually search for Available Networks. Wait for the list to appear then click on o2. You should see a brief message saying the phone has registered to the network. Go back to home screen and try placing a call again. Hope this helps.