How to Check a Phone's IMEI Before You Buy

Every used phone has a serial number the industry uses to track whether it was reported lost or stolen, whether it’s still being paid off, and whether carriers will activate it. Checking it takes about ten minutes and costs nothing.

Skipping it is how people end up with a device that gets rejected at trade-in, refuses to activate, or was stolen from someone last month.

What an IMEI is

The IMEI (International Mobile Equipment Identity) is a 15-digit number unique to a handset. It identifies the physical device — not the SIM, not the account, not the owner. Swapping SIMs doesn’t change it, and neither does a factory reset.

Carriers and manufacturers use it to look up a device’s status in shared databases. When someone reports a phone lost or stolen, its IMEI goes on a blacklist that participating carriers honour, and the device becomes difficult or impossible to activate on their networks.

Dual-SIM phones have two IMEIs; eSIM-only models still have one. Check whichever the seller provides, and be alert to a seller who supplies only one of two.

Getting the number

Four ways, in rough order of reliability:

Dial *#06# on the keypad. The IMEI appears immediately. Works on essentially every phone, requires no unlocking, and is the fastest thing to ask a seller to do.
Settings → About phone (Android) or Settings → General → About (iPhone).
The SIM tray or the back of the device, laser-etched on many models.
The original box, printed on the label.

For a remote purchase, ask for a photo of the *#06# screen. For an in-person purchase, dial it yourself on the actual device before any money moves — a seller’s screenshot of some phone’s IMEI proves nothing about the phone in front of you.

Running the check

Free IMEI checkers are widely available, and carriers publish their own device-eligibility lookups. Paid checks — usually a dollar or two — return more detail, including carrier of origin and, on some services, activation-lock status.

For a trade-in purchase, run two:

A blacklist / lost-and-stolen check. The critical one. It tells you whether the device has been reported.

The receiving carrier’s own eligibility lookup, if the carrier you’re trading into publishes one. This matters most, because theirs is the database that will judge your device. A handset that’s clean on a generic checker but flagged on the carrier’s own system will still be rejected.

Do both before paying. For a local meet-up, do both while standing there — two minutes on your own phone.

Reading the results

Clean / not blacklisted. Good, but not sufficient. It means no report has been filed yet. See the timing problem below.

Blacklisted / reported lost or stolen. Walk away. Not “negotiate the price down,” not “it might still work on another network.” Someone reported that phone stolen, it will be rejected at trade-in, and buying it puts you in possession of property reported as stolen. There is no version of this that ends well.

Financed / outstanding balance / “in use with a carrier.” The previous owner is still paying for it on an instalment plan. It isn’t fully theirs to sell, it can be blacklisted the moment they stop paying, and it will fail a trade-in ownership check. Walk away.

Activation locked. A different problem from blacklisting and just as fatal — the device is tied to the previous owner’s account and can’t be set up without their password. Covered in the phones you should never buy used.

Carrier-locked to a network. Not necessarily fatal. It may still be trade-in eligible, and it may be unlockable by the original carrier if the previous owner met their requirements. But it narrows your options and belongs in the price.

The timing problem

A clean check tells you the status at the moment you checked. It doesn’t prevent a report being filed afterwards.

The scenario: someone sells you a phone, then reports it stolen to their insurer or carrier. The IMEI is blacklisted days or weeks later. You have a device that checked clean, and now doesn’t.

You can’t eliminate this, but you can make it much less likely and much less costly:

Buy from sellers with history. An account with years of activity and feedback is a poor vehicle for this. A three-day-old account with stock photos is a good one.
Keep proof of purchase. A receipt, a message thread containing the IMEI, a payment record with a name attached. This is what protects you if the device is flagged later.
Prefer platforms with buyer protection when the amount justifies it. eBay’s money-back guarantee covers items not as described within its window; cash in a car park covers nothing.
Move quickly. Complete the trade-in soon after buying. Your exposure is the time you hold the device.
Re-check just before you trade in. Ten seconds, and it can turn a rejection into a return claim while a claim is still possible.

Listing red flags

Patterns worth treating as disqualifying before you even ask for the number:

Refuses to provide the IMEI, or sends a blurry, cropped, or obviously reused photo. There’s no legitimate reason to withhold it.
The IMEI provided doesn’t match what *#06# shows on the device in person.
Priced far below every comparable listing, with urgency attached.
“Locked to previous owner, easy to unlock” or any variant. That’s an activation-locked device sold as fixable. It isn’t.
Multiple identical listings from a new account.
Won’t meet, won’t ship tracked, wants payment by an irreversible method.

The short version

Before money moves:

Get the IMEI from *#06# on the actual device.
Run a blacklist check.
Run the receiving carrier’s eligibility lookup.
Confirm it isn’t activation locked and isn’t still financed.
Keep a record of the seller and the transaction.

Ten minutes, and it removes nearly every way this goes wrong. The rest is covered by the in-person inspection procedure.