Most lockouts have a quick fix. You're outside the car, your keys are inside — a mobile locksmith arrives, opens the door, you're back on the road in 30 minutes.
But this article is for a different situation. The one where you've already been through the lockout. You've already turned the house upside down. You've checked the same coat pocket nine times. You've called every place you visited in the last 48 hours. And you've slowly, sinkingly realised:
You don't just need someone to open the car. You need a brand-new key. And there is no spare.
This is called an "all keys lost" situation in the auto locksmith trade, and it sounds catastrophic. It isn't. Here's exactly what to do, what it costs, and why you almost certainly don't need to tow your car to a main dealer.
It sounds dramatic but the definition is simple: you have no working key to the vehicle. Could be that you lost both keys, or only ever had one and it's gone. The car can't be started, can't be opened (or it's already open from a previous unlock), and there's no way to authenticate a new key against the existing electronics.
Until about 1995, this was a relatively trivial problem. A locksmith could cut a key from the lock or the VIN, and the car would start.
Modern cars are different. Since the late 1990s, almost every car has an immobiliser system. The immobiliser requires the car to recognise a chip inside the key (called a "transponder") before the engine will start. Even if a key fits the physical lock perfectly, the car won't start unless the chip is also recognised.
So replacing a "lost key" isn't just cutting metal anymore — it's cutting AND programming. Both have to happen for the car to actually work.
When you're in this situation, you have exactly two real options.
You arrange to tow the car to a Mercedes / BMW / Ford / Toyota / etc. dealership. They:
Typical total cost: £400-£1,200 depending on car Typical timeline: 3-14 days from first contact to driving away Plus: towing costs (£100-£300)
A mobile auto locksmith comes to wherever your car is. They:
Typical total cost: £150-£400 depending on car Typical timeline: 1-3 hours on-site for most vehicles Plus: no towing required — the technician comes to the car
For the vast majority of "all keys lost" situations, Option 2 is dramatically cheaper, faster, and just as effective. A reputable mobile locksmith uses the same diagnostic protocols and key types as the dealer. The difference is mostly about cost structure — dealers carry overheads that mobile services don't.
If you call a mobile auto locksmith for an "all keys lost" situation, here's what to expect:
You'll be asked:
If the locksmith can do the job, you'll get a price quote on the phone before anything else happens. Get this in writing (text message, WhatsApp, email).
The technician arrives at the car. Before anything else, they verify ownership:
This isn't bureaucracy for its own sake — it's the legal line between "auto locksmith service" and "vehicle theft assistance." A locksmith who skips this is one to avoid.
The technician either:
Total time on-site: typically 1-3 hours from arrival to driving away.
Exact pricing depends heavily on the vehicle. Some realistic UK mobile locksmith costs:
These are typical ranges, not guaranteed prices. Every quote is vehicle-specific. The locksmith should be willing to give you an exact price on the phone before dispatching.
For comparison, main dealers for the same work commonly quote £400-£1,200 — plus towing costs.
Have these ready before calling:
You don't need all of these to call and get a quote — but you'll need most of them when the technician arrives.
If you've lost your only car key:
We cover Greater London, Kent, Essex, Surrey, and Sussex. Most "all keys lost" jobs are completed within 24 hours of your call — usually same-day. All work is backed by warranty (typically 6 months to 2 years depending on the job).
Once you've lost a key — especially if it had any identifying information on it (vehicle keyring, address tag, anything) — it's worth thinking about the security implications.
A serious mobile locksmith will reset the immobiliser when programming the new key, which means any lost or stolen keys can no longer start the car. This is the most important security step. Insist on it.
If you're particularly concerned about theft — particularly with newer, higher-value vehicles — a Ghost 2 immobiliser installed at the same time as your new key is worth considering. It adds a PIN sequence that even a stolen new key can't bypass.
How long does the whole process take? Typically 1-3 hours on-site from the technician arriving. Plus phone diagnostics and travel time, count on 3-4 hours total from your first call.
Can a locksmith really program a Mercedes / BMW / Range Rover key? For the vast majority of models built in the last 15 years, yes. Newer flagship models (e.g. brand-new Range Rover Sport, Tesla, BMW iDrive 8 vehicles) may require dealer access for the latest software versions. Ask on the phone before dispatching.
What if the locksmith damages my car? A reputable mobile auto locksmith carries professional indemnity insurance. Any damage is covered. Confirm this when getting your quote.
Will the new key work with my factory key fob features (remote unlock, alarm, etc.)? Yes, in most cases. The new key is functionally identical to the original — just programmed by a locksmith rather than the manufacturer.
Do I need to be present for the entire job? You need to be present for ownership verification and to test the new key. The actual programming can run in the background while you wait — bring a book, drink, or work to do.
What if I find my original keys after getting a new one made? The new key has been programmed and your old keys have been wiped from the car's immobiliser. The old keys are now decorative — they won't start the car anymore. This is the correct security outcome, but it's worth knowing.
Can I just buy a key online and program it myself? For most modern cars, no. You can buy a key blank online for £20-£50, but programming requires dealer-grade equipment that costs thousands. Even if you bought the equipment, most cars require a security token from the manufacturer to allow programming. Not a DIY job in 2026.
Lost your only car key and need a replacement?
Call 07777 676261 or WhatsApp us on +44 7777 676261.
For non-urgent quotes or to arrange a spare key while you still have a working one (much cheaper than waiting for a lost-key emergency), use our contact form.
Whatever you do — don't tow the car to the dealer yet. A 5-minute phone call to a mobile auto locksmith could save you hundreds of pounds.