Can You Program A Second-Hand Or Used Car Key?
Sometimes, and it can save money — but used fobs bring their own problems, and the part number matters more than the price.
- AVG Same Day Service
- DBS Checked
- 5★ Reviews
Not A National Company
A local business, not a call centre.
Real Local Professionals
Locals, not technicians sent by a middle-man company.
No Inflated Pricing
National companies often mark prices up 2–3x. We don't.
Deal Direct With The Technician
No wondering who or when. It's always us.
Sometimes — it depends on whether the fob can be reset
Some used keys can be cleared and re-registered to another vehicle of the same type. Others are locked to the first car they were paired with and can never be reused. Whether yours is reusable comes down to the key platform, the exact part number and the condition of the electronics inside.
Why Some Fobs Can Be Reused And Others Cannot
A key holds an identity. On some platforms that identity can be wiped and rewritten; on others it is written once and fixed for the life of the key.
Where a key can be reset, a used fob from a matching vehicle behaves like a new one after it is cleared. That is why used keys have a market at all.
Where a key cannot be reset, it will pair with one vehicle and one only. Buying such a fob second hand gets you a plastic case with a dead identity inside, regardless of how good it looks.
We can usually tell which situation applies from the part number and the vehicle's key platform, which is why it is worth asking before spending money rather than after.
What To Check Before You Buy One
Four checks that prevent most wasted purchases.
The exact part number
Not the model name — the number printed on the fob or its circuit board. Cars of the same model and year can use different parts depending on build and specification.
The frequency and region
Keys sold for other markets can look identical and transmit on the wrong frequency. A key intended for a different region may never operate your locking.
Whether it has been reset
A seller who can confirm the key has been cleared is offering something usable. A seller who cannot say is offering a gamble.
Physical condition
Water damage, a cracked case or corroded battery contacts will cause intermittent faults later, even if the key pairs on the day.
Used Fob Versus New Key
What you actually gain and give up by buying second hand.
| Used fob | New key supplied by us | |
|---|---|---|
| Up-front part cost | Usually lower | Higher |
| Certainty it will pair | Depends on the platform and history | Checked against your vehicle first |
| Condition | Unknown | New electronics and case |
| If it fails on the day | You have bought it anyway | We supply an alternative |
| Blade cutting | Still required | Included |
We are happy to work with a fob you have already bought. We will tell you honestly beforehand whether it looks usable.
The Part Everyone Forgets: The Blade
A used fob arrives cut to somebody else's car, so the mechanical side still has to be dealt with.
Depending on the key, that means cutting a new blade to your vehicle's code and fitting it into the used housing, or replacing the blade entirely. It is not difficult, but it is work, and it is why a cheap fob is rarely as cheap as the listing suggests once the job is complete.
On keyless proximity keys with an emergency blade hidden in the body, that blade still needs to match your car if you ever need it — which, on a flat vehicle battery, is exactly when you will.
Buying A Second-Hand Key Without Wasting The Money
If you are set on sourcing one yourself, a few checks decide whether it is usable.
Match the part number rather than the shape. Keys that look identical across a model range can carry different electronics inside, and a fob that fits your hand perfectly is no indication it will talk to your car. The number moulded or printed on the key, and the frequency it operates on, are what matter.
Check the blade profile separately. Even where the electronics are right, the blade may be a different pattern for your year or market, and it will need cutting to your vehicle regardless. A used key almost always arrives cut to somebody else's car.
Ask whether it has been paired before and to what. A key still registered to another vehicle is not automatically a dead end, but some types cannot be cleared and reused, and those are the ones that turn a bargain into a paperweight.
If you would rather not gamble, we can supply the key as part of the job. It arrives unused, it is the correct part for your vehicle, and if it fails it is ours to replace rather than a listing that closed three weeks ago.
Before You Bid On A Used Key
Four things worth confirming with the seller.
The donor vehicle
Make, model and year, not just the make. Keys change mid-generation, and a facelift can be the line between working and not.
The part number
Printed on the key or the circuit board. It is the only reliable way to match electronics rather than appearance.
Its current state
Whether it is locked to the donor car, already cleared, or unknown. Unknown is a risk you are accepting, not one you can price.
Condition of the case
Water damage and cracked cases are common on used keys and are not always visible in a photograph taken at arm's length.
Used key questions
Get a free quote in two quick steps
Send your details and we'll call you back with a price. For anything urgent, just call.
- Price explained before any work
- No upfront payment
- Deal direct with the technician
Got a used fob you want checked?
Send us the part number and your registration and we will tell you whether it can be programmed before you spend anything else on it.
“Excellent service for my BMW 3 series with failed manual lock that he repaired quickly, replacing worn cam. Cannot recommend too highly.”