Before trying other options, inspect your Samsung Galaxy S20’s SIM card tray. Follow these steps: Turn off your Galaxy S20. Use the SIM eject tool (or a paperclip) to open the SIM tray.

Samsung's Galaxy S20, S20 Plus and S20 Ultra have a standard SIM and an eSIM, as does the Galaxy Z Flip. The eSIM functionality may not be present at launch, but will be activated by a future update.

The SIM card is what gives your phone its identity — it holds your Samsung Galaxy S10's phone number and other identifying information for the cellular network. It might also contain your contacts.

Samsung Galaxy S20 SIM-free Cosmic Grey, £564.23 (save £236) - buy here; All prices in this article were correct at the time of writing, but may have since changed.

SIM Card Compatibility: Confirm that your SIM card is compatible with the Samsung Galaxy S9. Incompatible or outdated SIM cards may not work correctly with your device.