Key Takeaways
- Always verify that a used device is not locked to a carrier or a previous owner's account before paying.
- Battery health is one of the most important — and most overlooked — things to check on any used device.
- Physical condition matters, but software and account status matter just as much.
- Buying from a seller who provides proof of purchase gives you meaningful recourse if problems emerge.
- Run every port, button, camera, and speaker before you commit — not after.
Summary
18 items · 20–45 minutes
Why Secondhand Devices Deserve a Proper Inspection
Used gadgets — smartphones, tablets, laptops, wireless earbuds — can offer genuine value. But unlike buying new, you inherit whatever history the device carries: a worn battery, a cracked inner display you can't see at a glance, or an account lock that renders the device unusable the moment the previous owner changes a password.
The good news is that most problems are detectable if you know what to look for. This checklist walks you through the key checks to make — ideally in person, before money changes hands. Pair it with our privacy checklist for new devices once you've made your purchase, because used devices may still carry the previous owner's data and settings.
If you're also considering making informed everyday purchases more broadly, the same principles apply: slow down, verify, and don't let urgency override due diligence.
A SIM card from a different carrier
Used to test whether the device is carrier-unlocked and can connect to a different network.
Bright flashlight or phone torch
Helps reveal hairline screen cracks, port corrosion, and liquid damage indicators not visible in normal lighting.
Diagnostic app (e.g. a battery or hardware test app)
Provides structured checks for battery health, sensors, and hardware components on Android devices.
Wi-Fi hotspot or nearby network access
Lets you verify the device's Wi-Fi radio connects and holds a signal during inspection.
The Full Pre-Purchase Checklist
Work through these groups in order. If you're buying remotely, request video evidence of each step and use a payment method that offers buyer protection.
Account and Lock Status
Physical Condition
Battery Health
Hardware and Functionality
Software and Updates
Account Locks Can Make a Device Worthless
An activation lock — Apple's iCloud Lock or Google's Factory Reset Protection — can prevent anyone other than the original owner from using the device. A seller may not disclose this, and it may not appear until after a factory reset. Always confirm account status is fully cleared before completing any payment. If a seller is unable or unwilling to demonstrate this, walk away.
Remote Purchases Carry Higher Risk
When buying used devices online or by mail, you cannot physically inspect the hardware before paying. If you proceed, use a payment method that offers documented buyer protection and request timestamped video of every checklist step. Be especially cautious with deals that seem priced significantly below market — this is a common signal of hidden damage or a locked device.
After You've Decided to Buy
Once you're satisfied with the inspection, ask the seller for any original accessories, packaging, or proof of purchase. A receipt or order confirmation confirms ownership history and can be essential if a warranty claim is ever possible.
After you take ownership, run a full factory reset before setting the device up as your own — this clears any residual accounts, apps, or personal data from the previous user. From there, building good habits matters. See our guide on habits that keep devices running longer to protect your investment from day one. And if you're managing several devices in your household, common device management mistakes are worth understanding before they become your problem.