Contact your mobile carrier and report the IMEI number
Ask the carrier to block the device and check if they can help locate it
File a police report and provide the IMEI number
Use your phone’s built-in tracking service if it was enabled
Check Google Find My Device for Android phones
Check Apple Find My for iPhones
Log in to your Google or Apple account from another device
Review recent device activity in your account security settings
Contact the phone manufacturer for support
Keep the IMEI number ready for insurance claims or replacement requests