Bought a Used Car With One Key? Do This Now
Book a spare key and have the missing keys erased from the car in the same visit, because the relearn that registers your new key is the same operation that stops any key you were not handed from starting it. From £65 at your address across Leeds.
The worry most people have about this is the correct one. You have no way of knowing whether the second key was lost four years ago or is sitting in a drawer somewhere, and the car cannot tell you either. It starts for any key still stored in it, regardless of who is holding that key or how the sale went.
That is fixable in one visit and it costs far less than most people expect. What follows is what to do about it, what it costs, and the checks worth doing if the money has not changed hands yet.
The Key You Were Not Given Still Starts the Car
This is the part that keeps people awake rather than the cost, and almost nothing written about buying a car with one key addresses it properly. The car does not know it has been sold.
An immobiliser stores a list rather than a single key, commonly four to eight slots depending on the make. Every code sitting in that list will start the engine.
A seller who says the second key was lost years ago may well be telling the truth. There is no way to prove it from outside the car, and a private seller often does not know either.
The paperwork records the vehicle and the registered keeper. It says nothing at all about how many keys exist or who is holding them.
Most missing keys genuinely were lost. The point is not that you have been cheated, it is that you cannot verify it and you do not have to live with the doubt.
A car driven away on a key the immobiliser already recognises leaves none of the signs that a forced entry does. No broken glass, no damaged lock, nothing to photograph. That is precisely the situation worth closing off, and closing it off is a twenty minute job on your driveway.
Why the Car Came With Only One Key
Worth understanding before you decide what it means, because in most cases it means very little. Four ordinary explanations cover almost every car that arrives this way.
The commonest reason by a distance. One goes missing, the remaining key works perfectly well, and replacing it never quite reaches the top of the list.
A car traded in often arrives with one key because the second stayed in a drawer at the old address. It then goes out to the next buyer exactly as it came in.
Vehicles that spent their working life with a fleet or on lease were frequently only ever issued a single key in the first place.
A dealer quote running into the hundreds is enough to make most people decide to live with one key. That decision is usually why the car reaches you the way it does.
A single key is common enough that on its own it is not a reason to walk away from a car. What matters is not how it happened but what you do about it once the car is yours, and how quickly.
Erasing the Missing Keys Happens While the Spare Is Cut
Here is the part almost nobody is told, and it is the reason these two jobs should never be booked separately. They are not two jobs.
On most vehicles registering a new key is not an addition. The tool clears the stored key codes and writes back only the keys physically present in that session.
Any key not in your hand at that moment is no longer recognised by the car. It will open nothing and start nothing, whoever is holding it.
Because the erase and the new key are the same operation, having both done together is one job on one visit rather than two separate call outs.
The session has to have at least one working key in it, which is exactly the situation you are in. Leave it until that key is lost and the job becomes a different and dearer one.
Say that you have just bought the car, that you were given one key, and that you want the keys you did not receive deleted at the same time as the spare is cut. It is the same twenty to thirty minutes on the driveway either way, and asking for it after the engineer has packed up means booking a second visit.
The process is the same one used when every key to a car has been lost, where the stored list has to be rebuilt from nothing. That version is set out in full in the all keys lost walkthrough, and it is the expensive version of what you can have done cheaply today.
What One Key Takes Off the Value
Asked constantly and almost never answered with a number. The honest answer is that the deduction should be whatever a spare costs, and in practice it is usually a good deal more than that.
A buyer thinking clearly deducts what it costs to put right, which for most cars sits between £65 and £150 rather than the figures usually quoted.
A buying service or a part exchange valuation commonly removes a round sum in the low hundreds, because it is a flat policy applied to every car rather than a quote for yours.
Spending £65 to remove a deduction of two or three times that is the rare piece of car spending that returns more than it costs.
Two keys takes a question out of the advert. A car listed with one key invites negotiation before anybody has even seen it.
If you are reading this having already bought the car, the figure matters less than the timing. Have the spare made now and you own a two key car, which is what you will be selling in three or four years time.
Where You Stand If a Dealer Sold It to You
Two separate questions get muddled together here. Whether selling a car with one key is allowed, and whether you were told about it, are not the same thing at all.
No rule requires two keys with a used car, and a sale with one is a perfectly valid sale. That is the answer to the question most people are really asking.
Where the advert, the invoice or the sales paperwork said two keys and one arrived, that is a different situation entirely and worth raising straight away.
The strongest moment is while the deal is still open. Accepting the car knowing it has one key makes the same conversation much harder a fortnight later.
Asking for something towards the cost of a spare is an ordinary request at the point of sale and is often met, particularly while the car is still being prepared.
A short message to the dealer confirming that the car arrived with one key, sent the same day rather than the following week, costs nothing and puts a date on the record if the conversation carries on.
What a Spare Costs Now Against a Lost Key Later
The whole argument for doing this today sits in the gap between the top of this table and the bottom of it.
Prices are from, at your vehicle, with no VAT and no call out fee. Every row above assumes the key you were handed still works, which is what makes them the cheap rows.
That last row is the one to look at twice. While your key works, a spare can be cut and coded from it in half an hour. Once it is gone, the replacement has to be generated from the vehicle identification number and coded from scratch, which is the lost keys job and starts at more than double. Full figures by make sit on the car key replacement cost guide.
The Checks Worth Doing Before Money Changes Hands
For anyone reading this still deciding rather than already committed. Four checks, none of them taking more than a minute, and the first one is the one people skip.
Pull the metal key out of the fob and turn it in the driver door lock. A blade that does not fit the lock the car was built with is the single check most worth doing.
Obvious and skipped constantly. Start the engine with that key, lock and unlock the car with it, and do all of it before the money moves.
Ask how many keys the car has had and what became of the second one. The answer, and the manner of the answer, both tell you something useful.
A two minute call with make, model and year gives you a real number to negotiate with instead of a guess, and the guess is nearly always too high.
The metal key inside the fob should turn in the driver door lock the car was built with. Where it does not, something about that car and its locks does not add up, and it is far better to understand why before anything is signed than afterwards.
If the car passes all four and still comes with one key, that is a car worth buying with a number in your head. The cutting and coding side is quoted on make, model and year in about sixty seconds, so the number is easy to get before you agree anything.
Questions Before You Call
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One Visit. A Spare Cut and the Rest Erased.
Spare keys from £65, no VAT, at your address across Leeds.
34 makes covered. All Leeds LS postcodes. No call-out fee.