When you find your car key fob not working, it is usually a cheap fix and you rarely need a main dealer to resolve it. A modern car key contains a transponder chip to start the engine and a remote control to open the doors. Both elements must match your specific vehicle to work, but an auto locksmith can repair or replace them quickly on your driveway.
Start with the simple checks
A modern car key performs two completely different security jobs. The buttons operate the remote central locking to open the doors and the boot. Inside the plastic head of the key, a transponder chip allows the engine to start, and it must be programmed to match your car.
Most cars built after 1998 have transponder chips programmed to a specific car. The RAC says the transponder should only work with your vehicle. If you press the remote and the doors do not unlock, the fault may be in the remote, the transponder or the key itself, and an auto locksmith can tell you which.
Check your car handbook for what to do when the fob stops working, including how to get in with the key if you have a keyless entry fob. Car-specific advice belongs in the handbook, and an auto locksmith can diagnose the fault if the handbook does not help.
Why a new battery is the cheapest first step
Car key fobs run on small batteries, and replacing the battery is the cheapest first step because the cost is so low.
According to the Master Locksmiths Association (MLA), a replacement car key battery should cost from £4 fitted. An auto locksmith can fit the battery for you, and at that price it is usually not worth risking damage to the fob by prising it open yourself.
Worn buttons and a damaged fob
If a new battery does not fix the problem, ask an auto locksmith to check the buttons and the circuit board inside the fob.
The MLA states that car key fob buttons soldered onto the circuit board will cost from £20. Replacing just one button will be a lot cheaper, with prices starting from £5 per button.
Sometimes the metal blade snaps off inside the ignition or becomes too worn to turn the door lock smoothly. The price to repair a car key with a snapped or worn blade is from £20, which applies to all car key types from remote fobs to transponder keys. Ask the locksmith whether the repair can keep your existing fob.
When the fob needs reprogramming
The chip in a modern key must be programmed to match your car. The MLA says a replacement or repaired fob will need reprogramming, and a locksmith who specialises in reprogramming key fobs can help.
A damaged transponder key or remote fob needs an auto locksmith who specialises in key programming.
The MLA gives no price for reprogramming. The RAC notes that some providers add a fee to program or code a modern key on top of the physical key cost. You must ask the locksmith to include the programming cost in their total price before you agree to the work.
What a locksmith can do that you cannot
Auto locksmiths are a separate specialism covering vehicle entry, key cutting, transponder and remote programming. The MLA says auto locksmiths can programme remote car key fobs and repair damaged or broken keys.
If you are locked out, ask the locksmith how they will gain entry and whether any damage to the car is likely before they start.
Do not try to reset, resync or bypass a car security system yourself. Check the car handbook for any specific advice, and then ask a professional auto locksmith.
Typical 2026 prices for fob repairs and remotes
Jobs are usually priced as labour plus parts, either by the hour or as a fixed price per job. The price is driven by the time of day, your location and the type of key you need. Evenings, nights, weekends and bank holidays cost more, while rates in London and the South East are generally higher than the rest of the UK.
Here are the typical estimates for repairing an existing key fob.
|
Problem |
Typical price |
|---|---|
|
Replacement battery fitted |
From £4 |
|
One button replaced |
From £5 |
|
Buttons soldered to circuit board |
From £20 |
|
Snapped or worn blade |
From £20 |
These figures are 2026 estimates published by the MLA, and each locksmith sets their own prices.
If your fob cannot be repaired, you will need a completely new key cut and programmed. The MLA advises that remote and transponder keys need programming by a specialist auto locksmith, not just cutting. Non-remote car keys can start from £45, while remote and proximity keys can average from £100.
When a fob fails entirely and you have no working backup, the cost rises significantly. Keys cost the most when you have no spare because there is no original to copy.
Here are the typical replacement figures for a completely new remote or keyless entry fob.
|
Key type |
Typical replacement cost |
|---|---|
|
Replacement or spare car key (RAC) |
Between £250 and £400+ |
|
Remote key |
Around £320 |
|
Keyless entry key |
Around £280 |
The RAC figure covers a replacement or spare key and notes that some providers add a fee to program or code a modern key. The remote and keyless figures are typical 2026 prices for the whole replacement job. Treat these as separate ranges and do not combine them with each other or with the MLA prices above. Local quotes will differ.
Locksmith or main dealer
When a car key fob stops working, many drivers assume they must tow the car to the franchised dealership. This is rarely the case. The MLA explains that an auto locksmith is usually the cheapest option and can programme remote car key fobs and repair damaged or broken keys.
A franchised dealership is the most expensive and slowest route for a key replacement. They may need to order a key blank, which adds delay.
Many auto locksmiths are mobile, so ask whether they can come to you and whether they can finish the job in one visit. Some garages charge a fee just to use their diagnostic software. If you are unsure which option suits your budget, read our guide on choosing an auto locksmith or main dealer for vehicle keys.
How to get quotes and what to ask
There is no government licensing of locksmiths in the UK. Anyone can trade as one, which means you must vet the person you hire to protect your vehicle. The MLA operates a voluntary approval scheme where approved companies are vetted, have criminal record checks, employ locksmiths who have passed an exam and are inspected regularly.
The MLA advises getting at least three quotes from different auto locksmiths before agreeing to any work. Tell them the exact make, model and registration year of your car so they can check their software.
Ask these questions to ensure you get a firm total price:
- Does the quote include the call-out charge and the physical key?
- Is the cost of diagnostic programming included in the final price?
- Does the total figure include VAT?
- Can you complete the repair or replacement at my current location?
- Will you disable the old key in the car computer if it cannot be fixed?
- Are there extra fees for evenings or weekends?
Many locksmiths charge no separate call-out fee but some do, so you must ask. Explain your situation clearly to decide if the job is urgent. If you are locked out in a dark car park at night, you will have to pay an emergency out-of-hours rate. If the car is safely parked on your driveway, wait until normal daytime working hours to avoid premium charges.
Be aware of the common scams used by rogue traders. Watch out for these warning signs when booking a repair:
- National call centres advertising as a local locksmith and passing the job to whoever is nearest.
- A very low price quoted on the phone that multiplies on the doorstep.
- Refusing to give a total price before starting work on the vehicle.
- Demanding cash only and refusing to provide a written invoice.
- Arriving in an unmarked vehicle with no company name, address or ID.
Under the Consumer Rights Act 2015 a service must be carried out with reasonable care and skill, at a reasonable price if none was agreed, and within a reasonable time. You have a right to have poor work put right or your money back. Under the Consumer Contracts Regulations 2013 there is normally a 14-day cancellation period for work arranged at home or by phone. This does not apply where you specifically asked for a visit for urgent repairs, although extra work sold during that visit is not covered by the exception.
Keeping a working spare
Relying on a single car key is a significant financial risk. When your only key fob stops working, you have no backup to start the engine or open the doors. Keys cost the most when you have no spare because there is no original to copy.
If your current fob is showing signs of wear, such as stiff buttons or a loose blade, act before it fails completely. Having a second key cut and programmed while the first one still functions is much cheaper and faster than starting from scratch. You can read more about getting a spare car key made to protect yourself against sudden electronic faults. If your fob is missing entirely, check our advice on what to do if you have lost your only car key and have no backup at home.
Common questions
Can I buy a replacement fob online?
Ask an auto locksmith before you buy one. The chip must be programmed to match your car, and the MLA says remote and transponder keys need programming by a specialist, not just cutting.
Does a flat battery mean the key needs reprogramming?
There is no firm rule that applies to every car. Check the car handbook, and ask an auto locksmith if the key still does not work after a new battery.
Will my car insurance cover a broken fob?
Cover differs between policies, so check your own policy wording or ask your insurer.
Can a locksmith open the car if the fob is completely dead?
An auto locksmith covers vehicle entry as part of their work, so this is a job to hand to one. Ask how they will get in and whether any damage is likely before they start.
Next steps
When your car key remote stops responding, follow these steps to get back on the road safely without overpaying.
- Check the car handbook for advice on what to do when the fob stops working.
- Ask an auto locksmith to fit a new battery before paying for anything more involved.
- If the buttons or blade are damaged, ask for a repair quote rather than buying a whole new key.
- Get a total price that includes parts, labour, programming and VAT before booking a visit.
- Check that the locksmith has a real local address, reviews over time, and ask to see their ID when they arrive.
A broken fob is a frustrating problem, but it rarely requires an expensive trip to the main dealer. To get a firm price for a battery, a button repair or a fully programmed replacement, you can find a locksmith near you.
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