Can I tell if someone changed my sim card

[AC Question]

I think my sim card has been exchanged I have a galaxy 6+ edge and it keeps giving me a default error every time I call or text

 

[BattleSwine]

The way I know to keep track of the SIM number is to keep the "card" the SIM came in. Compare number the printed on card to info about phone in settings. You don't have to pull the SIM.