Open the Settings app

Tap General

Tap About

Find the IMEI number in the list

Dial *#06# on the Phone app

The IMEI will appear on the screen

Check the SIM tray on some iPhone models

The IMEI may be printed on the tray

Check the back of the iPhone on some older models

The IMEI may be printed there

Look on the original iPhone box

The IMEI is usually printed on the barcode label

Connect the iPhone to a computer

Open Finder on Mac or iTunes on Windows

Select the device and view the IMEI in the device summary

Check your Apple ID device list

Sign in to your Apple account and view the device details