iPhone Buying 10 min read
Alin Marin — CEO Radical Service
Alin Marin CEO Radical Service

Over 12 years of experience in Apple repairs · 25,000+ devices repaired · ASE Bucharest

Used iPhone Check: 21-Point Checklist

What you check on the spot, what you ask the seller to do, and how to spot an iPhone with hidden issues before you pay.

21

Check points

15-20 min

Inspection time

3

Non-negotiable conditions

100%

Free, you do it yourself

Used iPhone check

✓ The 3 non-negotiable conditions

If any of these three is missing, don't buy regardless of price or explanations. The rest of the checklist is for negotiation.

  • IMEI verified — not blacklisted, not reported as stolen on imei.info or codat.ro
  • iCloud disconnected — seller signs out of the account in front of you, on the spot
  • Battery at least 80% — under 80% means replacement soon, negotiate or refuse

Complete checklist — 21 checks

Some you do yourself directly on the phone. Others you ask the seller to perform. Don't rush — a good iPhone deserves 15-20 minutes of inspection.

A

Documents and identification

3 points
1

IMEI and serial number

Go to Settings → General → About. Note the IMEI and Serial Number. Verify immediately on imei.info or codat.ro — the phone must not be blacklisted or reported as stolen. This is the most important step of the entire checklist.

2

Box and proof of purchase

If it comes with the box, check that the serial on the box matches the serial on the phone. Ask for the original proof of purchase — without it, Apple warranty is void.

3

Country of origin

Check on imei.info which market it was initially activated in. Phones brought from Asia or US are legal, but Apple support may be limited and some models don't have 5G for Romanian networks.

B

Ownership checks

4 points
4

iCloud Lock / Activation Lock

Ask the seller to go to Settings → iCloud and disconnect the account NOW, in front of you. If they say they can't or that they'll do it later — don't buy. An iPhone with iCloud Lock is completely unusable without the original account password.

5

Find My iPhone

Check Settings → [Username] → Find My → Find My iPhone. It must be disabled. If it's still active after the seller claims to have signed out of iCloud, the process wasn't completed correctly.

6

Screen Time Passcode

Try to enter Settings → Screen Time. If it asks for a passcode the seller doesn't know, restrictions remain active and can't be removed without that code. Ask for it to be disabled before purchase.

7

SIM Lock (carrier-locked)

If the phone came from US or UK, it may be locked to a specific network (T-Mobile, AT&T, EE). Ask for proof of unlock or test with your SIM on the spot.

C

Battery

3 points
8

Battery Health

Settings → Battery → Battery Health & Charging. Ideal: 85%+. Acceptable with negotiation: 80-85%. Under 80% — price must include battery replacement cost (300-500 RON). Under 70% — refuse or negotiate a major discount.

9

Original or replaced battery?

Settings → General → About → iPhone Parts. On iPhone 15 and newer, iOS indicates whether the battery is original Apple or has been replaced. A good-quality replaced battery is OK — an "unknown" one or without warranty is risky.

10

Discharge behaviour

Keep the phone on 10-15 minutes with WiFi active. Does it behave normally? A phone that suddenly drops from 30% to 5% or shuts down unexpectedly has a more worn battery than the Settings percentage shows.

D

Screen and display

2 points
11

Cracks, dead pixels, lines

Open an image with pure white background (Settings → Wallpaper or photograph a white sheet). Look carefully in good lighting. Any dead pixel, vertical line or dark area means the screen will need replacement — cost 800-2,000 RON depending on model.

12

Brightness, colours and uniformity

Set maximum brightness. Uniform colours across the entire surface? No area more yellow or cooler? "Burn-in" marks (ghost images) appear on intensively-used OLED screens and can't be repaired — the entire panel is replaced.

Used iPhone verification checklist
E

Cameras

3 points
13

Front camera and Face ID

Open Camera and switch to selfie. Image clear? Autofocus working? Test Face ID — it should unlock quickly from normal use angles. If Face ID doesn't work, repair costs 400-600 RON.

14

Main camera (back)

Take a well-lit photo. Autofocus works (tap to focus)? Lens clean inside, without dust or condensation? Also check video mode — OIS stabilisation works smoothly?

15

Telephoto (if available)

On iPhone 15 Pro+ and 16 Pro+, test 3x, 5x or 10x zoom. Image stays clear and stable? If the lens makes noise or doesn't switch smoothly, the zoom motor may be damaged.

F

Audio and sensors

3 points
16

Speaker and microphone

Play a song at maximum volume — sound should be clean, without crackling or distortion. A speaker that's been in contact with water sounds "drowned". Test the microphone with a short voice recording.

17

Vibration (Taptic Engine)

Settings → Sounds & Haptics → test vibration intensity. The Taptic motor should produce clear and precise vibrations, not weak or irregular ones. A weak motor indicates wear or previous impact.

18

Touch ID (older models)

On iPhones with Home button (SE, 8 and older), scan 2-3 different fingers. Touch ID should work fast and consistently. If it doesn't recognise, the sensor may be damaged or unofficially replaced.

G

Connectivity

2 points
19

WiFi, Bluetooth, 5G

Connect to a WiFi network — connection speed and signal should be normal. Activate Bluetooth and check if it finds devices. If none of the wireless connections work correctly, it may be an antenna issue (complex repair).

20

Charging port (USB-C or Lightning)

Connect a cable — it should go in easily and firmly, without needing force or a special angle. If the port is oxidised, loose, or requires holding the cable in a specific position to charge, replacement costs 300-500 RON.

H

Exterior and liquid damage

1 point
21

Case, corrosion and water indicator

Fine scratches are normal on a 2-3 year old phone. What should worry you: cracks in the aluminium case, green-brown corrosion near connectors, or the red water indicator. The indicator is located near the SIM slot — if it's red, the phone has been in contact with liquid. Internal corrosion progresses slowly and can lead to failures in 3-6 months even on a phone that currently appears functional.

How to interpret the results

✓ Buy

All 3 basic conditions OK + maximum 1-2 minor points (superficial scratches, battery 80-85%).

↓ Negotiate

2-3 points with real issues (battery 75%, port slightly damaged, screen with scratch). Calculate repair costs and subtract from price.

✗ Refuse

iCloud Lock active, red water indicator, IMEI blacklisted or seller refuses any check. No price is low enough for these situations.

Frequently asked

What is iCloud Lock and why is it so important?

iCloud Lock (Activation Lock) ties the iPhone to the owner's Apple account. If the seller doesn't disable it before sale, after you buy the phone iOS will ask you for the original account password to reactivate it. Without that password, the phone is completely unusable. Always ask for it to be disabled in front of you, on the spot.

How do I verify the IMEI correctly?

Dial *#06# on the phone or go to Settings → General → About → IMEI. Access imei.info or codat.ro and enter the number. Verify the phone isn't blacklisted, hasn't been reported as stolen, and the model in the database matches what you see in front of you.

What Battery Health is acceptable?

85%+ is ideal. 80-85% is acceptable if the price reflects this. Under 80% means the battery will need replacement soon — the cost (300-500 RON depending on model) must be subtracted from the asking price. Under 70% refuse or negotiate a major discount.

What happens if Face ID doesn't work?

You can unlock the phone with the PIN code, but Face ID is an essential feature and its absence significantly reduces device value. Repair costs 400-600 RON (TrueDepth module replacement). If the seller doesn't acknowledge the issue, negotiate with the repair amount.

Can an iPhone that has been in water be bought?

Avoid. Even if it works now, internal corrosion progresses over time. Connectors, battery and board circuits degrade progressively. A phone with red water indicator or visible corrosion near connectors has a high failure risk within 3-6 months.

Not sure what to buy?

Bring the used iPhone to us before you pay. We do a complete diagnostic and tell you exactly what issues it has and how much fixing them costs. English-speaking team.

40 Aristotel Pappia St., Sector 1, Bucharest · Mon-Fri 08:30-17:30