25 September 2026
8 min read
Worthing Auto Locksmith
A replacement key fob costs between £130 and £250 from a mobile auto locksmith for a standard remote, and between £180 and £400 for a keyless smart fob. A new battery costs around £15.
That spread is the whole problem with this question. Key fob replacement covers four different jobs, and the cheapest of them costs about a fortieth of the dearest. Everything below sorts out which one applies to you before it talks about money.
What a key fob replacement costs
The table covers the four jobs and the three fob types, with the main dealer price alongside for comparison. Figures are UK ranges for 2026 and a price for one specific car comes from the registration rather than from a table.
| What you need | Mobile auto locksmith | Main dealer |
|---|---|---|
| A new battery in the fob you have | £10 to £20 | £25 to £50 |
| A repair to the fob you have | £50 to £120 | Not usually offered |
| Reprogramming a fob you already own | £50 to £150 | £80 to £200 |
| A flip key supplied, cut and programmed | £100 to £200 | £200 to £400 |
| A remote fob supplied, cut and programmed | £130 to £250 | £250 to £500 |
| A smart proximity fob supplied and programmed | £180 to £400 | £400 to £800 |
| Losing every key, added to the above | £50 to £150 | Plus recovery |
Two rows cover most people. A remote fob on an ordinary car from the last fifteen years, and a smart fob on anything keyless from roughly 2015 onwards. Fobs supplied and programmed are quoted from the registration before anybody sets off.
Which of the four jobs you need
Four jobs sit behind the same four words, and being in the wrong one is how people end up paying three hundred pounds for a fifteen pound problem.
The battery has gone. The range got shorter over a few weeks, then the buttons stopped working, and the car still starts with the fob held against the marked spot. This is a coin cell and nothing else.
The fob is damaged. A cracked case, a button that has worn through, a blade that flops, or a fob that went through a wash. The electronics and the chip inside are usually fine, which makes key fob repairs the cheaper half of this page.
The fob has lost its pairing. It looks perfect and the car ignores it. Nothing needs supplying, so the cost is the programming alone.
The fob is gone or beyond repair. A new one is supplied, the blade is cut and the fob is written to the car. This is the job most people mean, and it is the one the table prices in its middle rows.
Why the part is not the price
This is the question underneath the question. A fob on an auction site costs less than a tank of fuel, and a locksmith quotes two hundred pounds for what looks like the same thing.
Four things are being paid for, and the fob is the smallest of them.
- The fob itself. A genuine one costs real money and an aftermarket one costs very little, which is the next section
- Cutting the blade to match the locks on that specific car, which needs the code the manufacturer holds
- Writing it to the car, which means getting into the immobiliser and adding a key the security system will accept
- Coming to the car and doing all of it where the car is parked
The third one is where the money actually goes. Programming a modern immobiliser needs equipment that costs thousands to buy and carries an annual software subscription on top, because manufacturers change the security on their vehicles constantly and access has to be kept current. That cost sits behind every job whether the fob was fifteen pounds or two hundred.
What changes the price on your car
Five things move the number, listed here from the largest effect downwards.
Whether a working key still exists. By a wide margin the biggest lever. With a working key the new fob is added alongside it, which is quick. With no working key at all, the fob has to be generated from the vehicle itself and the security system is dealt with from scratch, which adds between fifty and a hundred and fifty pounds.
Keyless or not. A smart key replacement costs more than a remote fob on the same car, because the part is dearer and the programming is longer.
The model year. Newer vehicles carry tighter security, and the newest few years on some makes are where independent access narrows and prices climb.
The make group. Volume makes sit at the bottom of every band. German and premium marques sit at the top, and a small number of vehicles need a part that only the manufacturer supplies.
How many fobs. A second fob programmed during the same visit costs far less than the same fob on a separate visit, because the setup work happens once.
Aftermarket fobs against original fobs
An original fob is the part the manufacturer supplies. An aftermarket fob is a compatible part made by somebody else. The price difference is large, and so is the honest answer about when it matters.
On a great many cars an aftermarket fob is genuinely fine. It cuts, it programmes, it locks and unlocks, and it starts the engine. Most volume vehicles from the last twenty years fall into this group, and using one is how a quote comes in at the lower end of a band rather than the upper.
On some vehicles it is a false saving. On certain makes within the Volkswagen group in particular, a poor quality remote can leave the component security data on the car in a compromised state. The fob works for a while, and the problem surfaces later as a fault that costs several hundred pounds to unpick. Fifty pounds saved on the day becomes a much larger bill afterwards.
On a small number of vehicles only the original part works. Where that applies, the genuine remote alone runs to £280 or more before any work happens at all, which puts a complete job near £600. Any quote far below that on one of those cars is either fitting something else or has not been finished yet.
Which group a car sits in is settled from the registration, which is why it is worth asking outright whether a quote covers an original or an aftermarket part.
When a repair costs less than a fob
A repair beats a replacement more often than most people expect, and it is worth saying so on a page about replacement prices.
The electronics inside a fob rarely fail. What fails is everything around them. Cases crack, buttons wear through, blades work loose at the hinge, and battery contacts lift or corrode. All four are mechanical problems on a component whose expensive half is untouched.
The reason it saves so much is the chip. A repaired fob keeps the chip already paired to the car, so nothing needs writing to the immobiliser and the largest cost on this page disappears entirely. Remote car key repair covers the electronic side, and the case and blade side is the same visit.
What losing every key adds
Losing every key is a different job rather than a dearer version of the same one.
With a working key in hand, the new fob is added to a list the car already holds. With no key at all, there is nothing to copy and nothing to add to. The fob is produced from the vehicle itself and the security system is worked through from the beginning, which takes longer and needs more equipment.
That adds between fifty and a hundred and fifty pounds to the bands in the table on most cars. Car key replacement cost goes into the all keys lost situation properly, including what it costs when the key is a traditional one rather than a fob.
How to get an accurate quote
Every price on this page is a range. Five details turn a range into a number, and having them ready shortens the call to about a minute.
- The registration
- The year the car was built, which sometimes differs from the plate
- Whether a working key still exists
- Whether the car starts with a button or with a key in a barrel
- How many fobs are wanted
Two questions are worth asking back, whoever is quoting. Does the price include the programming, because a fob price without it is not a job price. And is the part original or aftermarket, because that is what separates two quotes on the same car.
A quote that covers both, given before anybody travels, is the one to trust. Where the comparison is with a franchised garage rather than between two locksmiths, a mobile auto locksmith against a main dealer sets out what actually differs beyond the number.
How to avoid the cost next time
Almost everything on this page becomes a small bill instead of a large one with a bit of foresight.
Get a second fob while the first one works. This is the whole of it. A fob programmed alongside an existing key costs a fraction of one generated from a car with nothing left, and the difference is larger than most people believe until they see the two quotes side by side. Spare car key cost has the figures.
Change the battery every two years. Not when it fails, on a schedule. It costs a few pounds and it removes the commonest fob complaint completely.
Keep the fob off a heavy keyring. Weight hanging off a fob works the case apart at the seams and loosens the blade, and both of those turn a five year fob into a three year one.
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