How to Inspect a Used Smartphone Before Purchase

Follow this essential checklist to verify hardware, software, and activation status of a used smartphone before finalizing your purchase.

Examine the exterior condition. Inspect the display for deep scratches, dead pixels, or pressure marks. Run your finger along the edges to detect screen separation, which indicates a swollen battery or previous repair attempt. Check the charging port for debris, corrosion, or signs of loose pins.
Check the activation lock status. Ensure the device is not linked to a previous owner’s account. On iPhone, navigate to Settings > General > About and confirm no 'iCloud Activation Lock' message is present. On Android, navigate to Settings > Security and ensure no Google account is currently signed in.
Verify cellular and wireless connectivity. Insert your active SIM card into the device to verify it connects to the cellular network and displays signal bars. Test a phone call to verify both the earpiece speaker and microphone function. Confirm Wi-Fi and Bluetooth connect to a known hotspot to verify the internal radios are operational.
Audit battery and charging performance. Check the battery health menu to ensure the maximum capacity is above 80 percent. Plug the device into a power bank for two minutes to confirm the charging circuit accepts a charge reliably. If the percentage does not increase or the device runs hot, the charging port or battery is degraded.
Test buttons and biometric sensors. Press every physical button to ensure tactile response and proper operation. Enroll your fingerprint or register your face for biometric authentication to verify the sensor hardware works. A faulty sensor often indicates a non-genuine screen replacement.
Check the device IMEI status. Dial *#06# to display the unique IMEI number. Enter this number into a reputable online carrier blacklist checker to confirm the device has not been reported lost or stolen. A 'Clean' status is required to ensure the phone can be activated on your carrier.