Hi @Andrej1299 Telegram will ask on the new device to register with your phone number. Then it will send a code that you'll have to enter. So as Bolly said, it's best to set your new phone first. What I do is set everything using WIFI, install the app and configure everything. Create a backup or transfer data to your new device (if they both run Focal) Then when everything is working on the new device, I switch SIM on a weekend, so I have time to mess things around if the mobile network does not work out of the box. Test everything out and you should be golden.