How do I use Dual SIM or USIM Cards on Galaxy S8 or Note8?
If you insert two SIM or USIM cards, you can have two phone numbers or service providers for a single device.
※ Note: If both cards are activated, you can receive calls and messages on each card.
However, if you are on a call using one card, the other card cannot be used to receive new calls.
Change Display Name and Icon of SIM Cards
Switch between Cards
When two SIM or USIM cards are activated, card selection icons appear on the dashboard of the notifications panel.
Open the notifications panel (Drag from the top of the screen downwards with one finger) and then select the card to be used.