Buying a Used Car: Why You Should Check How Many Keys Come with It
When you buy a used car, ask how many working keys come with it — two is the healthy norm. A second key proves the car still accepts key programming, saves you from an emergency all-keys-lost job, and costs far less to duplicate while the first key works. Test every key on the car before money changes hands.
Most used car buyers check the mileage, the service history and the tyres — then accept whatever keys the seller hands over without a second thought. That is a mistake. Keys are part of what you are buying, and on a modern car they can be the most expensive single part to replace. A missing key is not a minor detail; it is an unresolved problem you are about to pay for twice.
A spare key is the cheapest protection against the day one goes missing, which is why our guide to why every driver needs a spare car key is worth a read before you start viewing cars. This guide covers what to ask, what to test, and what to do if the car you want only comes with one key — and if you are already holding a single-key car, our notes on how to pick a reliable auto locksmith in Worcestershire will help you get it sorted properly.
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One working key is a warning sign, not a detail
A used car sold with only one working key is a car with an unresolved problem. The missing key may be genuinely lost, it may be sitting in a drawer at a previous owner address, or it may have broken and never been replaced. Each of those possibilities creates a cost or a risk that lands on you the moment you drive away.
The security angle matters as much as the cost one. If a previous owner still holds a working key, they can open and start the car you just bought. That is rare, but it is exactly why a missing key deserves questions rather than a shrug. Ask the seller directly, listen to the answer, and factor it into what you are willing to pay.
What the second key actually proves
Two working keys tell you something important about the car electronics: the immobiliser system still accepts key programming. On most modern cars the immobiliser checks a chip in the key before the engine is allowed to start, and new keys are added to the car computer through a programming procedure. A car that already has two working keys is a car where that system is healthy.
The second key also gives you an immediate backup. Lose your only key on the first week of ownership and you are facing an all-keys-lost job — the most involved and therefore the most expensive kind of key work. With a second key in a drawer at home, the same bad day becomes a minor inconvenience and a planned spare-key visit.
Ask about keys early in the negotiation
Do not leave the key question until handover. Ask when you first speak to the seller: how many keys come with the car, and are they all working? A straight answer — two keys, both tested — is what you want. Evasion, vagueness or a promise to find the spare later should lower the price you offer or end the deal.
If the seller promises a missing key will turn up, get it in writing on the receipt or advert before you pay. A written promise gives you something to stand on if the key never appears. And never complete the purchase before you have tested every key yourself, in person, on the car.
Test every key before you pay
Testing takes five minutes and answers every question that matters. Work through each key one at a time, and do not accept a key that only half works — a remote that unlocks but will not start the car is not a working key.
If any key fails any check, treat it as a missing key and negotiate accordingly. A key that needs a new battery is a trivial fix; a key the car does not recognise may need full programming or replacement.
| Check | How to test it | Why it matters |
|---|---|---|
| Remote locking | Lock and unlock the car from a few metres away | Confirms the fob buttons, battery and receiver all work |
| Engine start | Start the engine with each key in turn | Proves the transponder chip is recognised by the immobiliser |
| Physical blade | Turn the blade in the driver door lock | Shows the cut key matches the locks if the remote ever fails |
| Boot or tailgate | Open the boot with the key or fob button | Catches keys that work the doors but not the boot release |
| Spare key in full | Repeat every check with the second key | A spare that only opens doors is not a spare at all |
Why used cars end up with only one key
There are honest reasons. Keys get lost by previous owners, fobs break and never get replaced, and fleet or lease cars sometimes return with one key after years of drivers. Repossessed and auction cars frequently arrive with a single key and no history at all. The seller may genuinely not know where the other key went.
The reason does not change what you should do: price the car as a one-key car. You are the one who will pay to put the situation right, so the purchase price should reflect that. A calm, factual conversation about key replacement cost — which varies by make, model, year and key type — usually gets a fair adjustment.
Your day-one job: get a spare cut
If you buy a one-key car, make a spare key your first job, not a someday job. Cutting a second key while one working key exists is straightforward work: the blade is copied, the chip is programmed to the car, and you drive away with a backup. Wait until the only key is lost and the same car becomes an all-keys-lost job — slower, more involved, and harder on your wallet.
This is also the moment to think about where you will store the spare safely, because a spare key in the glovebox is barely better than no spare at all. Keep one at home, somewhere a burglar would not look first.
A mobile auto locksmith can cut and program the spare at your home or workplace, usually in a single visit — our car key replacement service explains how the visit works and what we need from you.
Need help with a single-key car?
Bought a car with only one key, or viewing one this weekend and want to know what a spare would involve? Tell us the make, model and year and we will give you a straight answer and a clear quote before any work starts. Call or WhatsApp 07367 634032 — we cover Alvechurch, Bromsgrove, Redditch and Birmingham South, 24 hours a day.
Frequently asked questions
How many keys should a used car come with?
Two working keys is the normal expectation. One key is common enough that you should ask why, test what you have, and price the car accordingly.
The seller says the spare is lost. Should I still buy the car?
You can, but treat it as a one-key car: test the remaining key fully, ask for a price reduction, and budget for a spare key as your first job after purchase.
Could a previous owner still have a working key for the car?
It is possible, which is why a missing key is a security question as well as a cost question. Ask the seller directly, and consider having the car memory cleared of old keys when you get a spare made.
Is a spare key cheaper from a dealer or a locksmith?
A mobile auto locksmith is usually the lower-cost and faster option, with the work done at your location. Dealers can supply keys too, but expect a higher price and a wait. Costs vary by make, model, year and key type.
What do I need to get a key made for a car I just bought?
Proof that the car is yours — typically the V5C logbook or purchase receipt plus photo ID. A professional will verify ownership before cutting or programming any key.