Sim cards are items, each containing a phone number in their metadata. When a sim card is created (purchased or given via commands/scripts) it will not contain a number.
Players will have to open the sim card once, via the inventory or the phone, which will generate the new number for that item.
When using a sim card, the previous phone number equipped in the phone will switch places with the current number in the sim card item.
This phone number swap is done via settings → phone details → sim cards
