Productcheck 05

Buying a used
smartphone .

A phone can look new while hiding a worn battery, screen damage or an account lock. Use this check to test an iPhone or Android phone before paying.

01Account lockmust be removed
✓IMEInumber must match
Take your timeTest the phone for at least five to ten minutes
Bring alongCharging cable, SIM tool and optionally your own SIM
Pay particular attention toAccount lock, IMEI, battery and screen

Before you leave

Ask these questions first.

Ask for the exact model, storage capacity and a photo of device information. 'iPhone' or 'Galaxy' alone is not enough.

01

Who owns the phone?

Ask for proof of purchase and the IMEI or serial number. The seller should clearly explain where and when it was bought.

02

What has been repaired?

Ask about replacement screen, battery, camera, rear panel or charging port. Also ask about impact, moisture and water damage and repair receipts.

03

How is the battery now?

Ask about normal runtime, unexpected shutdowns and any battery replacement. Check this on the phone later.

04

Why is it being sold?

The answer should fit age, condition and price. Agree which cable, box, cases and any warranty are included.

The most expensive surprises

Accounts and battery
check these first.

An account lock can make a phone unusable. A weak or non-original battery can also affect performance, runtime and safety.

01

Remove all accounts

An iPhone must not retain the previous owner's Activation Lock. On Android, the seller must correctly remove their Google account before the factory reset. Complete the reset together.

02

Compare the IMEI

Display the IMEI in settings or with *#06# and compare with casing, box and receipt where possible. Check it on Stop Heling, the Dutch stolen-goods database; no match is not a complete guarantee.

03

Check battery health

An iPhone shows battery health and warnings in settings. Android varies by brand; use built-in diagnostics where available and watch for rapid drain, heat and shutdowns.

04

Check management and updates

Look for unknown work or school profiles, management messages and locks. Check the software version and whether the exact model still receives security updates.

Inspect the whole product

Six components to test every time.

01

Screen & touch

Use light and dark backgrounds. Look for cracks, marks, burn-in, flickering and dead pixels. Drag an icon slowly around all edges to test touch response.

02

Casing & moisture

Remove the case. Inspect corners, seams, camera glass and back for dents, gaps, rust, condensation and loose adhesive. A bulging back may indicate a swollen battery.

03

Cameras & flash

Test every front and rear lens, near and far. Take photos and video with sound. Watch for persistent marks, blur, shaking and failure to focus.

04

Buttons & sound

Test power, volume, vibration, speakers, microphones and earpiece. If possible, make a short call and listen at both ends.

05

Charging & connections

Connect a compatible cable and check charging starts immediately and stays steady. Test wireless charging if needed. The port should not work only in one cable position.

06

Network & sensors

Test Wi-Fi, Bluetooth, mobile connection, GPS, proximity sensor and face or fingerprint recognition. Check SIM or eSIM compatibility with your provider.

The quick practical test

Five revealing minutes.

Test all functions before removing accounts and erasing the phone. An already erased phone is harder to assess fully.

  1. 01

    Minute 1 — identity

    Compare model, storage and IMEI with advert and documents. Restart fully and watch for errors, management screens and odd startup logos.

  2. 02

    Minute 2 — screen

    Try high and low brightness, light and dark backgrounds and touch response at every edge. Check buttons and biometric unlocking.

  3. 03

    Minute 3 — image and sound

    Take a photo and video with each camera. Play them back, test flash, speakers and microphones, and listen for crackles or dropouts.

  4. 04

    Minutes 4–5 — connection and reset

    Test Wi-Fi, Bluetooth, mobile network and charging. Then have the seller remove accounts, erase through Settings and demonstrate activation for a new owner is possible.

!

Do not buy if...

Four reasons to walk away.

Checking mode

Tick off points during
your viewing.

0%

0 van 12
points checked

01Ownership & access
02Battery & casing
03Functions & reset
Your progressTake your time with the list. Making a call or seeing the home screen is not a full smartphone check.

This check helps you test carefully but offers no guarantee. Water resistance of a used or repaired phone cannot be reliably established during a viewing. If unsure about an expensive device, seek professional assessment.

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Everything tested and erased?
Only then pay and set it up yourself.

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