How to check a used iPhone before you buy

Buying a used iPhone is a smart way to save money, but it requires a careful inspection to avoid hardware issues or locked devices. This guide will walk you through the essential steps to verify a phone's condition and authenticity before you finalize the purchase.

Verify the IMEI and Activation Lock

The most important step is ensuring the phone is not stolen or locked to a previous user. Go to Settings, then General, and then About to find the IMEI number. You can use online tools to check if this number has been reported as lost or stolen. Additionally, make sure the Activation Lock is turned off. If the phone asks for a previous owner's Apple ID during setup, do not buy it. It is also helpful to use BuyLow AI to compare prices for that specific model across various marketplaces to ensure the asking price is fair and reflects the phone's current market value.

Check the IMEI in settings
Ensure Find My iPhone is disabled
Verify the device is paid off
Confirm it is not carrier locked

Inspect the Physical Condition

Examine the exterior of the iPhone under good lighting. Look for cracks in the screen or back glass, and check the edges for dents or scuffs that suggest it was dropped. Pay close attention to the camera lenses to ensure they are not scratched or cracked. Check the charging port for debris or signs of damage, and try plugging in a charger to see if it connects immediately. Press all the physical buttons, including the volume rockers, the silent switch, and the power button, to make sure they are clicky and responsive rather than mushy or stuck.

Check for screen and back glass cracks
Test all physical buttons
Inspect the charging port for damage
Look for scratches on camera lenses

Test the Display and Touch

Turn the screen brightness all the way up and down to check for dead pixels or discoloration. A good way to test this is by opening a blank white image and a blank black image. Check for 'ghosting' or areas where the touch response is laggy. Move an icon around the entire screen to ensure there are no dead zones where the touch fails. If the phone has Face ID or Touch ID, test these features several times to confirm they work perfectly, as these are expensive components to repair if they are faulty.

Check for dead pixels or bright spots
Test touch sensitivity across the screen
Verify Face ID or Touch ID works
Check for True Tone in display settings

Evaluate Battery Health

iPhone batteries degrade over time, and a worn-out battery can significantly impact performance. Go to Settings, then Battery, and then Battery Health to see the Maximum Capacity percentage. A healthy used phone should typically have a capacity above 80 percent. If it is lower, you may need to pay for a battery replacement soon. Also, check for a 'Service' message, which indicates the battery is significantly degraded. While you are in settings, check if there are any messages about non-genuine parts, which could mean the screen or battery was replaced with inferior third-party components.

Check Maximum Capacity percentage
Look for non-genuine part warnings
Ensure the battery is not swelling
Check for unexpected shutdowns

Test Audio and Connectivity

Make a quick test call to ensure the earpiece and microphone are working clearly. Open the Voice Memos app and record a short clip to test the primary microphone. Play a video or some music to check the stereo speakers for any crackling or distortion. You should also toggle the Wi-Fi and Bluetooth on and off to ensure they can find and connect to nearby devices. If possible, insert your own SIM card to verify that the phone recognizes the network and can receive a signal, which confirms the cellular antenna is functioning correctly.

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Questions

What is Activation Lock?

Activation Lock is a security feature that prevents anyone else from using an iPhone if it is lost or stolen. If a used phone is still linked to the previous owner's Apple ID, you will not be able to set it up or use it. Always ensure the seller has signed out of iCloud and erased the device.

How can I tell if an iPhone has water damage?

Most iPhones have a Liquid Contact Indicator inside the SIM card slot. You can see it by removing the SIM tray and looking inside with a flashlight. If the indicator is red or pink, the phone has been exposed to water. If it is white or silver, it is likely fine.

Is it okay to buy a phone with a replaced screen?

It depends on the quality of the replacement. If it was done by Apple, it should be fine. However, third-party screens might lack features like True Tone or have poorer color accuracy. Check the 'Parts and Service History' in the General settings to see if the parts are recognized as genuine.

Should I buy a used iPhone that is carrier-locked?

It is usually better to buy an unlocked iPhone so you can use it with any carrier. A locked phone limits your options and may still be under a payment plan. If the previous owner stops paying the bill, the carrier could blacklist the device, making it unusable on any network.

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