Car key programming and replacement

A modern car key does two jobs: it operates the locks, and it carries a chip the car must recognise before the engine will start.

What car key programming means

Cutting the metal blade is the easy part; the chip has to be coded to that specific car. An auto locksmith or a garage with the right equipment can do both, often for less than a main dealer.

What the job covers

Spare and replacement keys cut and coded
Lost-key programming with all keys lost
Key fob battery and case repair
Immobiliser and transponder faults
Keyless-entry module coding

When you might need it

You are down to one working key, which is the moment to act rather than after it is lost.
The fob works intermittently, which is often just the battery.
The car turns over but will not start, and an immobiliser light is showing.

What it costs, and what changes the price

Typically £90 to £350.

A spare cut and coded while you have a working key costs least.
All keys lost is more involved, because the car's security data has to be read first.
Keyless entry fobs cost more than a traditional key with a blade.

How long it takes

A spare key is usually under an hour. All keys lost can take two to three hours.

Common questions

Can I get a key cut from the registration?

A locksmith can usually obtain the key code from the registration and V5C, with proof that the car is yours. That proof is required and any reputable firm will ask for it.

Is a locksmith cheaper than the dealer?

Often, yes, and many will come to the car. The work is the same as long as they have the right equipment for your make.

My fob has stopped working. Is that the chip?

Usually it is the battery, which is a coin cell and costs very little. The immobiliser chip needs no power and normally outlives the fob.