How to check an iPhone’s IMEI and blacklist status before you buy

Bought a used iPhone that won’t connect? That one call could have saved you hours and money.

What you should check first

Start by asking the seller for the IMEI or serial number. The IMEI is a 15-digit code that uniquely names the phone. Ask for it before meeting. If the seller hesitates, treat that as a red flag.

Once you have the IMEI, check three things: carrier blacklist status, activation/lock status, and whether the device is reported stolen. These checks tell you if the phone will work on your network and if it could be seized later.

How to run the basic checks (fast and free)

Write the IMEI down. Compare it to the number in the phone by opening Settings > General > About and looking at IMEI. If they don’t match, walk away.

Call or text the seller while you hold the phone. Ask them to accept a video call and show the Settings screen with the IMEI. This verifies the number is real and matches the device.

Where to pay attention: carrier and activation locks

Ask which carrier the phone is locked to and whether the seller can remove the lock. Locked phones won’t work on other networks until the lock is removed. Check the phone’s Activation Lock for Apple ID. If the phone asks for someone else’s Apple ID at startup, it’s still linked to that owner. If the phone is locked, ask the seller to sign out of iCloud and remove the device from their account while you watch.

Micro-moment

You meet the seller at a coffee shop. You ask for the IMEI. They hand over the phone and walk you through Settings. You spot a different IMEI on the box. That mismatch is an instant deal breaker.

Red flags and what to do next

If any of the following are true, pause the sale or negotiate hard: IMEI on phone doesn’t match paper or box. Seller refuses a quick video call or to sign out of iCloud. Phone shows Activation Lock or asks for another Apple ID. Device is listed as blacklisted or stolen when you check. The price is much lower than market with no reason given.

If you find a problem, ask for a lower price that reflects the work you’ll need to do, or walk away. Do not accept a verbal promise that the seller will "fix it later." Get proof now.

Testing the phone in person

Bring your own SIM card from the carrier you plan to use. Insert it and try to make a call, send an SMS, and use mobile data. Also check Wi‑Fi and Bluetooth, the touchscreen, cameras, and speakers. A quick test catches many hidden faults.

Check battery health in Settings to see how much life is left. Low battery health can mean replacement costs soon. If the phone needs a battery, factor that into your offer.

Negotiation levers and fair offers

If the device is carrier-locked, reduced price should reflect the work to unlock it or the cost of buying a compatible plan. If Activation Lock is present and the seller won’t remove it, do not buy.

For a clean, unlocked, fully working iPhone with decent battery life, aim for known local resale price minus any repair or unlocking costs. If you are not comfortable estimating repair costs, add a buffer to your offer or ask a repair shop for a quick estimate before buying.

Final checklist before you hand over cash

• IMEI matches the phone and any box or receipt.

• Device accepts your SIM and makes a call.

• Activation Lock is off and seller signs out of iCloud while you watch.

• No signs of water damage or heavy repairs.

• Battery health checked and acceptable.

• Seller provides a written receipt with your name, serial/IMEI, and date.

Bottom line and practical tips

Never buy a used iPhone sight unseen. A few minutes of checking the IMEI and testing the phone will save you hours of headaches. If something feels off, you can usually do better by walking away.

Bring the right cable and do a three-minute menu test — most deal-breakers show up fast.

Today’s takeaway: Don’t pay full price until the IMEI matches, the phone accepts your SIM, and Activation Lock is removed.