Open the Settings app on your iPhone
Tap General
Tap About
Scroll to IMEI (or IMEI1/IMEI2) and note the number(s)
Open the Phone app
Dial *#06#
View the IMEI number(s) on the screen
Check the iPhone’s original packaging label (if available)
Look for the IMEI/Serial number section on the SIM tray label (if present)
Check the SIM eject tool/SIM tray area for printed IMEI/Serial info (varies by model/region)
On a connected computer, open iTunes (or Finder on macOS)
Select your iPhone
Find the IMEI/Serial number in the device information section