Before you buy a used phone

1. Check the IMEI matches

Every phone has a 15-digit IMEI. Dial *#06# on the phone's keypad to show it. On an iPhone it is also in Settings → General → About, and on the original box's barcode label. Some iPhone models also have it on the SIM tray; iPhone 14 models and later have no IMEI engraving.

The IMEI on screen, in Settings, on the box and in the seller's listing should all be the same. The first 8 digits (the TAC) identify the model: enter them below to check that the phone is the model the seller says it is. The lookup uses the Osmocom TAC database and runs in your browser.

Sources: GSMA Device Check: FAQs · Apple: Find the serial number or IMEI on your iPhone

2. iPhone: Activation Lock must be off

Activation Lock comes on automatically with Find My, and links the iPhone to the owner's Apple Account. Without that account's password nobody can erase and reactivate the phone, so a locked iPhone is useless to a new owner.

If you see "iPhone Locked to Owner" when you turn it on, do not buy it. If you see the Lock Screen or Home Screen, the phone has not been erased: ask the seller to erase it in front of you. Then start setup. If it asks for the previous owner's Apple Account, hand it back and ask them to remove it. The phone is ready when you reach the "Hello" screen.

Sources: Apple: Activation Lock for iPhone and iPad · Apple: If you want to buy a preowned iPhone

3. Android (Samsung, Pixel and others): the Google account must be removed

Android's Factory Reset Protection links the phone to the owner's Google Account. After a reset done without the owner's permission, the phone asks for that account (or the old screen lock), and if you cannot give it you cannot use the phone at all.

Ask the seller to remove their Google account in Settings (on Samsung: Settings → Accounts and backup → Manage accounts → the Google account → Remove account), then do a factory reset from Settings in front of you. When you set the phone up, it should not ask for the previous owner's account.

Sources: Android Help: Help prevent others from using your device without permission · Android Help: Add or remove an account on Android · Samsung UK: How do I delete all of my personal information from my device?

4. Check it is not locked to a network

On an iPhone, open Settings → General → About. "No SIM restrictions" next to Carrier Lock means it is unlocked; a carrier name means it only works with that carrier.

On any phone, put your own SIM in, make a call and use mobile data.

Sources: Apple: If you want to buy a preowned iPhone

5. Check battery health where the phone shows it

iPhone (iPhone 6 and later): Settings → Battery → Battery Health (Battery Health & Charging on iOS 16.1 and later) shows the maximum capacity and any service message. It is not shown for unknown or non-genuine batteries.

Pixel 8a and later: Settings → Battery → Battery health shows "Normal" or "Reduced"; Reduced means capacity is below 80%. Older Pixels from the 6a to the 8 Pro do not show a status.

Samsung Galaxy: open the Samsung Members app → Support → Phone diagnostics, then Battery status. It shows Normal, Weak or Bad.

Compare with the rated cycles on the EU label for that model.

Sources: Apple: If you want to buy a preowned iPhone · Pixel Phone Help: Understand your Pixel battery · Samsung UK: How to check the battery status on your Galaxy phone

6. iPhone: look at the parts and service history

On iOS 15.2 and later, Settings → General → About shows a Parts and Service History section if the iPhone has been repaired. "Genuine" means genuine Apple parts and processes; "Unknown" can mean a non-genuine part, an unfinished repair or a part that is not working as expected; "Used" means the part was previously in another iPhone. Which parts are listed depends on the model.

Sources: Apple: iPhone Parts and Service History · Apple: If you want to buy a preowned iPhone

7. Stolen phones: what you can and cannot check

We know of no official EU-wide stolen-phone register that the public can search. Network operators share lost and stolen IMEIs through the GSMA's global Block List, and the public can see whether an IMEI is on it, but only devices that a participating operator or approved company reported are listed. A "not flagged" result is not proof that a phone is clean.

So ask the seller for the original receipt or other proof of purchase, and check that its IMEI matches the phone. If the seller cannot explain where the phone came from, will not sign out of their account, or the price seems too good, walk away. If you think a phone is stolen, report it to the police, or to your mobile operator if you have already bought it.

Sources: GSMA: Block List Services Description · GSMA Device Check: FAQs

8. Receipt and warranty

If you buy from a business, second-hand goods are covered by the EU's 2-year legal guarantee too; some EU countries let the seller agree a shorter period, but never under 1 year, and it must be made clear when you buy. Goods bought from private individuals are not covered by these rules.

For an iPhone, Apple's Check Coverage page shows the model and any remaining Apple warranty from the serial number.

Sources: Your Europe (European Commission): Guarantees on goods bought in the EU · Apple: Check Coverage