The first 24 hours after a phone is stolen matter. Start with the platform recovery tool: Find My iPhone for Apple devices or Find My Device for Android. Try to lock the device, display a recovery message and preserve the last known location if available.
Next, contact your carrier. Ask them to suspend the SIM or eSIM, protect the phone number and explain their process for reporting the device. Have the IMEI ready if you saved it from settings, the box, invoice or account records.
Change passwords for your primary email, banking apps, cloud accounts and password manager if there is any chance the device was unlocked. Review active sessions and revoke access from the stolen phone where services allow it.
File a police report or insurance claim when appropriate. The IMEI is useful here because it identifies the exact device. Include the model, color, storage, serial number, purchase proof and any location information from recovery tools.
Do not trust messages claiming someone found your phone and needs your login details. Stolen-phone phishing is common. Recovery links should come from official Apple, Google, carrier or insurance channels, not random SMS messages.
