Navigate to Settings → If the previous owner’s name appears at the top, iCloud is still active.
Important: Ensure the seller fully signs out of iCloud in your presence.

Go to Settings > General > About
Look for “Carrier Lock” – it must read “No SIM restrictions.”
If it states “SIM locked,” the device is tied to a specific carrier.

• Inspect the stainless steel frame (or titanium edges on newer models) for deep dents, bends, or cracks.
• Inspect the bottom screws for any signs of rust.
• Press the Action Button – it should feel crisp and responsive.

• With the screen off, check for scratches, chips, or cracks.
• Test for OLED issues:
• Open a blank page in Notes and zoom in on white. Look for discoloration, yellowing, or image retention (burn-in).
• Display a pure black image in a dim room. Ensure no uneven patches or glowing spots appear.

Check both the rear camera array and front TrueDepth camera for:

• Cracks or scratches on the glass
• Cloudiness or debris inside the lens. Even minor flaws can significantly impact photo quality.

• USB-C Port: Look for lint, debris, or bent pins.
• Buttons: Test Volume, Action, and Side Buttons – each should offer clear tactile feedback.
• Alert Slider (if applicable): Should move crisply between positions without sticking.

Enter Diagnostics Mode or download a Touchscreen Test app from the App Store.
Swirl your finger across the entire screen to check for:

• Dead zones
• Phantom touches
• Unresponsive areas

Go to Settings > Face ID & Passcode and enroll your face.
Verify it works:

• In normal light
• In low light
• At different angles

• Open the Camera app – test every lens (Ultra Wide, Main, Telephoto).
• Record a short video with audio to check the microphone.
• Listen for unusual sounds from Optical Image Stabilization.
• Test the flash and switch between photo/video modes.

• Make a test call. Check earpiece, speakers, and microphone clarity.
• Play a song or video at high volume – ensure no distortion or buzzing.
• Test USB-C audio output with headphones if available.

• Wi-Fi: Connect to a network and load a webpage.
• Bluetooth: Pair with wireless earbuds or seller’s device.
• Cellular: Insert SIM; make a call and use mobile data.
• GPS: Open Maps with Location Services enabled.
• NFC: Check and test NFC.

Go to Settings > Battery > Battery Health & Charging
Check Maximum Capacity (see Apple’s iPhone battery guide):

• Above 90% → Excellent
• 85–90% → Good
• Below 85% → Consider replacement

• Proximity Sensor: Make a call and cover the top front sensor.
• Accelerometer/Gyroscope: Rotate screen; orientation should change smoothly.
• Ambient Light Sensor: Enable Auto-Brightness; screen should dim when covered.

1. Factory Reset: Go to Settings > General > Transfer or Reset iPhone > Erase All Content and Settings.
2. Complete Setup Yourself: Go through setup until reaching the home screen.

Going through a used iPhone checklist takes time, and some faults are hard to spot without the right tools. If you’d rather skip the risk, browse Apple iPhones at MobileRelation, where every device is inspected before it is sold.

Upgrading from an older phone? You can trade in your old iPhone and put the value towards your next device. Want to know what it is worth first? Read our guide on how much your phone is worth in Singapore.