Open your phone’s Settings app
Tap About phone or About device
Look for SIM status, SIM card status, or ICCID
Check the ICCID field to see the SIM card number
On iPhone, go to Settings > General > About and find ICCID
On Android, go to Settings > About phone > Status or SIM status
Remove the SIM card and read the printed number on the card if needed
Check the SIM card tray or the original SIM packaging for the number
Contact your mobile carrier if the number is not shown on your device