Buying a used phone on Marketplace, Craigslist or OfferUp

Updated November 3, 2026

Most bad used-phone deals aren't dramatic. The phone turns on, the screen looks fine, and the seller seems friendly. The problem shows up later: it won't activate, it only works on one carrier, or it gets locked weeks after you paid. A few minutes of checking before you hand over cash avoids most of that.

Before you meet: get the IMEI

Every phone has an IMEI, a 15-digit number that identifies it. Ask the seller for it in the chat. They can find it by dialing *#06#, or in Settings: on iPhone under General > About, on Android under About phone.

A seller with a real phone has no reason to refuse. If they won't share the IMEI, or keep changing the subject, that tells you something.

Check more than the stolen list

A phone can be clean on the lost/stolen list and still be a bad buy. Before you meet, find out:

Lost or stolen: has it been reported to a carrier? A reported phone may not work for calls or data.
iCloud (Find My), iPhone only: is it still linked to the last owner's Apple Account? Apple's own advice is not to buy an iPhone with Activation Lock on.
Carrier lock: does it only work with one carrier?
Samsung Knox Guard: is a lender or carrier able to lock it because it isn't paid off?
Model: is it the phone in the ad, with the storage you were promised?

At the meetup

Meet in a busy public place in daylight, and bring someone if you can.
Dial *#06# on the phone itself and make sure the IMEI matches the one you checked.
On an iPhone, open Settings > General > About. Next to Carrier Lock you want to see "No SIM restrictions" if you plan to use another carrier.
Put your own SIM in (or set up your eSIM if you can) and make a call.
Have the seller sign out of iCloud or their Google account and erase the phone in front of you. After the reset, the setup screen should not ask for their Apple Account or Google account.
Pay last, and ask for a written receipt with the IMEI and the seller's name.

What no check can tell you

An IMEI check shows what the databases say on the day you check. A phone can be reported or locked later. No check confirms the battery, the screen, water damage or replaced parts, so test those in person. And there's no public way to confirm a phone is fully paid off. If that matters to you, ask the seller to show a zero device balance in their carrier app.

Check the phone before you pay

One $1.99 report checks the lost/stolen list, iCloud (Find My), carrier lock and Samsung Knox Guard, with one plain answer. No account needed.

Check a phone for $1.99 See a sample report