Cutting, Coding, Programming: The Difference
Three words used interchangeably for three different jobs. Knowing which one you need is the difference between a $20 quote and a $265 one — and it stops you being sold the wrong thing.
Ring three locksmiths about the same key and you will hear three different words for what needs doing. Cut. Code. Program. They are not synonyms, they cost very different amounts, and most cars need two of the three.
This is worth five minutes because it is the main way people get overcharged. If you can name the job, you can tell whether a quote makes sense.
Cutting is the metal
Cutting shapes the blade so it physically fits your lock. A machine traces your existing key, or cuts to a code from the vehicle, and the result turns in the door and the ignition.
That is all cutting does. It is mechanical, it is quick, and on its own it is the cheapest thing in this article — a plain metal key starts from $20. If your car predates immobilisers, cutting is the entire job and you are done.
Coding is the chip
From the late 1990s onward, car keys carry a transponder chip in the head. Coding pairs that chip to your car's immobiliser so the engine will actually run.
This is where cutting alone stops being enough. A correctly cut key with an uncoded chip will unlock the doors and turn in the ignition, and the engine will cut out after a second. The immobiliser is not broken — it is refusing to run for a key it does not recognise.
Coding needs diagnostic equipment plugged into the car. It is why a car key costs more than a house key, and why the hardware store cannot finish the job.
Programming is the buttons and the fob
Programming is what pairs the remote functions — lock, unlock, boot release — and on a keyless car, the proximity detection that lets you start it with the fob in your pocket.
On a basic remote key, coding and programming often happen in the same session and people use the words interchangeably without much harm. On a smart key they are genuinely separate pieces of work, which is part of why smart key replacement sits in a higher bracket, starting from $265.
Which do you need?
Work down this list and stop at the first one that matches your car.
• Plain metal key, no plastic head, older vehicle — cutting only.
• Metal blade with a thick plastic head, no buttons — cutting and coding.
• Blade with buttons on the head — cutting, coding and programming.
• No blade at all, starts with a button — coding and programming. There may be a hidden emergency blade to cut as well.
If you have lost every key, add one more step regardless of type: the key has to be generated from the vehicle rather than copied from an existing one, which is a longer job. Our car key replacement page covers what that involves.
Why the words matter when you are getting quotes
A quote for "cutting a key" on a 2015 Corolla is either a misunderstanding or an underquote that will grow when the van arrives. A quote of a few hundred dollars to "program" a key for a 1994 ute is the opposite problem.
When you ring us from anywhere in Hamilton or the Waikato, tell us the make, model, year and registration, and whether you still hold a working key. Those four things decide which of the three jobs you need, and we can price it properly before anyone drives anywhere.
Common questions
What is the difference between cutting and coding a car key?
Cutting shapes the metal blade so it fits your locks. Coding pairs the transponder chip inside the key to your car's immobiliser so the engine will run. Most cars built from the late 1990s onward need both — cutting alone gives you a key that opens the door and will not start the car.
Is car key coding the same as programming?
Not quite, though the words get used interchangeably. Coding deals with the immobiliser chip that lets the engine start. Programming deals with the remote buttons and, on a keyless car, the proximity detection. On a simple remote key they often happen in one session; on a smart key they are separate work.
Can any locksmith code a car key?
Any locksmith can cut one. Coding needs diagnostic equipment that talks to your specific vehicle, and the equipment differs by manufacturer, which is why we ask what the car is before setting off rather than after arriving.
How much does coding a car key cost in Hamilton?
A key with an immobiliser chip starts from $120, cut and coded at your vehicle. A smart or proximity key starts from $265. Both are starting points rather than fixed prices — the make, model and year all move it, so ring with your registration for a firm figure.