What to check when buying a used phone

Whether you're buying for personal use or for resale, the checks are the same — only the priorities shift. This is the consolidated checklist: physical, software, financial, and conversational.

Before you meet the seller

Three things you should already know before driving to a meeting:

• Current market price for that exact model. Look up the live price on a buyback platform or a comparison site. Knowing the unlocked Grade A price gives you the ceiling; the asking price should be 30–50% under that.
• Common defects for that model. Each generation has known weak points (iPhone 13 corner adhesive, Galaxy S22 green tint, Pixel 6 modem issues). Know what you're looking for.
• The seller's reputation, if applicable. Marketplace seller has a profile? Read the past reviews. Brand-new account selling a flagship phone for half price is a red flag.

Physical inspection (3 minutes)

Hold the phone at arm's length under good lighting. Check:

• Screen: any cracks, scratches, dead pixels, edge separation, or "burn-in" outlines.
• Frame: dents along the edges, chips at the corners, signs of drop damage.
• Rear: cracks in the back glass (especially on iPhone 8+ and Galaxy S8+ — sealed-glass repair is expensive).
• Camera lens: hairline cracks in the lens cover. Check each lens individually.
• Buttons: press each one — power, volume, mute / alert slider. Should click cleanly without sticking.
• Charging port: shine a light into it. Looking for lint, corrosion, or bent pins.
• SIM tray: pull it out. Should slide cleanly, not stuck.

Software inspection (5 minutes)

Now power on and run through the inspection in how to test a used phone before paying:

1. Dial *#06# — verify IMEI matches SIM tray and box.
2. Run an IMEI blacklist check. Walk away on red.
3. Verify Activation Lock / FRP is off.
4. Check battery health.
5. Test screen, cameras, Face ID / fingerprint.
6. Confirm carrier-lock status.

Financial checks

Two things to verify before money moves:

• Device-payment-plan status. Carrier-locked phones may have unpaid DPP balance. The seller should show a "paid in full" email from the carrier. Without it, the carrier can blacklist the IMEI 30 days after you buy it.
• Apple Pay / Google Pay history. If you can swipe to the wallet on the lock screen and see active cards, the device is still tied to the previous owner's payment account. Have them remove all cards before transfer.

Questions to ask the seller

The right questions reveal a lot. Most honest sellers answer easily; sellers who hesitate or change their answers are a flag.

• "How long have you owned this phone?"
• "Do you have the original box and receipt?"
• "Have any parts been replaced — screen, battery, anything?"
• "Is it on a carrier payment plan, or paid in full?"
• "Why are you selling?"
• "Can you sign out of your iCloud / Google account right now?"

Red flags

Walk away if you see any of:

• The seller can't or won't run the IMEI check, or refuses to dial *#06# in front of you.
• The seller signs into the phone with their fingerprint but the lock screen shows someone else's name.
• "I'll sign out of iCloud at home" — every variation of this phrase ends with you holding a locked phone.
• The asking price is more than 40% below current market for the claimed grade.
• The IMEI on the screen and the IMEI on the SIM tray don't match.
• The seller wants only cash and refuses to meet anywhere except a private location.

The 30-second decision rule

If you've completed the inspection and any check failed, take 30 seconds before deciding. Negotiating down for a known issue is fine if you know the repair cost. Buying with unknowns is what makes used-phone purchases go bad.