How to check if a used iPhone is blacklisted
A blacklisted iPhone looks and works like any other — until you put a SIM in. Carriers share the IMEIs of phones reported lost, stolen or unpaid, and a phone on that list is refused by most networks in the world. It is the single most expensive mistake a buyer of a used phone can make, and it takes ten seconds to avoid.
What 'blacklisted' actually means
Every phone has an IMEI, a 15-digit number burned into its radio. When a phone is reported lost or stolen, or when a financed phone stops being paid for, the carrier adds that IMEI to the GSMA device registry — the blacklist. Networks that subscribe to it refuse to activate any IMEI on the list.
The block travels with the phone. A factory reset does not clear it, a new SIM does not help, and moving country only works until that country's carriers sync the list — which most now do.
Find the IMEI first
Dial *#06# on the phone and the IMEI appears on screen. On an iPhone you can also open Settings › General › About and scroll to IMEI. It is printed on the SIM tray of most iPhones and on the barcode label of the original box.
If the seller will not give you the IMEI before you meet, treat that as your answer.
Run the free blacklist check
Type the IMEI into the free IMEI blacklist check. The result says clean or blocked, and when a block is recorded it usually names the reason and the reporting country. The check reads the same GSMA data the carriers use.
A clean result is necessary but not sufficient: a phone can be clean today and reported tomorrow if it is still being financed. For a US carrier phone, run the carrier's own status too — Verizon and T-Mobile both show whether the device is paid off.
Check two more things while you are at it
Blacklist is about the network. Two other locks can make an iPhone useless to you: Find My iPhone (iCloud Activation Lock, which asks for the previous owner's Apple ID after every reset) and the carrier SIM lock. All three are free to check, and a phone that passes all three is a phone you can actually use.
Run the checks this guide talks about
Questions people ask
Can a blacklisted iPhone be unblocked?
Only by the carrier that reported it, usually when the outstanding balance is paid or the owner recovers the phone. There is no legitimate third-party unblock.
Will a blacklisted iPhone work on Wi-Fi?
Yes. The blacklist only stops cellular service. The phone still works as an iPod-style device on Wi-Fi, which is why sellers sometimes describe them as 'Wi-Fi only'.
Is a blacklist check the same as a Find My iPhone check?
No. Blacklist is the carriers' list; Find My iPhone is Apple's iCloud lock. A phone can be clean on one and blocked on the other. Check both.
How much does a blacklist check cost?
Nothing here. Every visitor gets a few free checks a day. Resellers can run unlimited checks through an account.