Short answer: Before paying for any pre-owned phone, check five things: it is not lost, stolen or financed (IMEI check), it is fully signed out of the previous owner's accounts (no Activation Lock or Google lock), the battery health is honest, every core function works in a two-minute hands-on test, and the seller will still exist tomorrow if something goes wrong. Miss any one of these and a bargain can turn into a paperweight.
Check 1 — The IMEI: is this phone clean?
Every phone has an IMEI number (dial *#06# to see it). It identifies the handset to networks. A phone reported lost or stolen can be barred from Irish and UK networks — it will look perfect in your hand and never connect. Reputable shops check IMEI status before resale as a matter of course; private sellers may never have heard of it. Also be cautious of phones still under a finance or contract plan: if the original buyer stops paying, the phone can be barred later.
Check 2 — Account locks: the invisible trap
Modern phones are tied to their owner's account. An iPhone with Find My still on carries Activation Lock; an Android signed into Google carries Factory Reset Protection. Both survive a factory reset — that is their job. The phone must arrive signed out, showing a fresh welcome screen, and be set up in front of you or come from a seller who guarantees it. A phone that "just needs the last owner's password" is not a bargain; it is unusable. Our trade-in guide shows the correct sign-out process from the seller's side.
Check 3 — Battery health, in numbers
On iPhone: Settings → Battery → Battery Health shows a percentage. On many Android phones: Settings → Battery, or the manufacturer's diagnostics. As a rule of thumb, above ~85% feels healthy for daily use; below 80% means noticeably short days and a replacement on the horizon. Neither is a deal-breaker if the price reflects it and a replacement battery is available for that model — just never pay full-health money for a tired battery.
Check 4 — The two-minute hands-on test
- Screen: open a white page and a black page; look for dead spots, lines, discolouration. Drag an icon slowly around every corner — touch must follow everywhere.
- Buttons and ports: click every button; plug a charger in — it should sit firmly and charge without wiggling.
- Cameras: front and back, photo and video, tap to focus near and far; look for spots or blur that do not wipe off (that can mean internal damage).
- Sound: play a voice note or video; test loudspeaker and earpiece with a quick call.
- Connectivity: your SIM in it — signal, a test call, Wi-Fi and Bluetooth toggle on.
- Face/fingerprint: set it up fresh; a phone whose biometrics cannot be reset or enrolled is a red flag.
Check 5 — The seller
Ask: Where did it come from? Has it been repaired, and with what parts? What happens if it fails next week? A good seller answers plainly. A local shop adds something no listing can — you can walk back in. At Royal Tech in Rathfarnham, Dublin, pre-owned phones are tested across all the checks above before they reach the shelf, and graded so the description matches the phone.
Red flags that should end the deal
- "It just needs the previous owner's password." No — it needs to not be sold. A locked phone cannot be legitimately unlocked by you.
- The seller will not let you insert your SIM. There is no innocent reason to refuse the single most basic test.
- The IMEI on the box, the settings and the SIM tray disagree. One of them is telling a story. Walk away.
- Pressure to pay in a car park, cash only, no receipt, "today only". Urgency is a sales technique for things that cannot survive scrutiny.
- A price far below every other listing for the same model. The discount is real; so is the reason for it.
Negotiating fairly (and spotting honest pricing)
A fair pre-owned price reflects model, storage, condition, battery health and what is included. If you find a genuine fault the seller missed — a tired battery, a scratched camera lens — naming it calmly and asking for the price to reflect it is reasonable; demanding flagship money off for a hairline mark is not, and good sellers will simply decline. The healthiest sign in any negotiation is a seller who has already priced the faults in and can show you the test results. That transparency is worth a few euro over a mystery bargain, every time.
Frequently asked questions
Is it safe to buy a pre-owned phone online?
It can be, from established sellers with returns and clear grading. It is riskiest from anonymous listings with no returns — you cannot run the hands-on checks until the money has moved.
What does "unlocked" mean, and why does it matter?
Unlocked means the phone works on any network's SIM. A network-locked phone may only work on one carrier — fine if that is your carrier, a nasty surprise otherwise. Always test with your own SIM.
Should the phone come with a charger and box?
Nice to have, not essential. What matters is the phone's condition and status. Original accessories simply add a little value and convenience.
New or pre-owned — which is right for me?
Our new vs pre-owned comparison weighs warranty, updates, battery and price to help you land on the right side.
How can I check an IMEI before buying?
Ask for the IMEI (or dial *#06# yourself during the hands-on test) and use a reputable online IMEI checker to confirm the model matches and the phone is not reported lost or stolen. A shop selling the phone will have done this already and can show you.
The phone looks perfect but has no box or charger. Problem?
Not by itself — people lose boxes. It simply removes a small plus point. What matters is the phone passing the checks in this guide, not the packaging around it.