Types of Car Keys and Which One Your Car Uses
The types of car keys are the mechanical key, the transponder key, the remote key, the flip key and the smart key, and the buttons, the blade and the way the engine starts show which one a car uses.
Inta-Lock Car Key Guides. Updated October 2026.
Every car key is built from the same short list of parts, a metal blade, a transponder chip, a remote transmitter and a battery. The type of a key is the set of those parts it carries, which is why two keys that look alike in the hand behave differently at the car.
The type decides what a spare or a replacement involves. A blade is cut, a chip is programmed and a remote is matched to the car, and each key type takes one, two or all three of those stages. Four checks with the key in your hand name the type before any call is made.
What Are the Main Types of Car Keys?
Five types of car key are in everyday use, the mechanical key, the transponder key, the remote key, the flip key and the smart key.
- Mechanical key. A mechanical key is a cut metal blade with no electronics. The blade turns the door lock and the ignition lock, and nothing else in the key takes part. It belongs to older cars built without an immobiliser.
- Transponder key. A transponder key is a cut blade with a small chip sealed in its plastic head. The immobiliser of the car reads the chip each time the key is turned, and the engine runs only for a chip the car recognises. The key has no buttons.
- Remote key. A remote key is a transponder key with lock and unlock buttons built into its head. The buttons work the central locking from a distance, and the blade and the chip still start the car in the ignition.
- Flip key. A flip key is a remote key with a blade that folds into the case and springs out at the press of a button. The electronics match those of a remote key, and only the way the blade is carried differs.
- Smart key. A smart key is a fob that stays in a pocket or a bag while the car unlocks and starts. The car senses the key nearby, the doors unlock at the handle and the engine starts from a button on the dashboard.
The names vary between makers. A key fob, a proximity key and a keyless key each describe a remote key or a smart key, so the parts inside the key are a firmer guide than its name.
How Do the Car Key Types Compare?
The car key types compare on four points, how the car is unlocked, how the engine is started, whether the key holds a battery and what a new key of that type needs.
| Key type | How it unlocks the car | How it starts the engine | Battery inside the key | What a new key needs |
|---|---|---|---|---|
| Mechanical key | The blade is turned in the door lock | The blade is turned in the ignition lock | None | The blade cut to the locks of the car |
| Transponder key | The blade is turned in the door lock | The blade is turned in the ignition lock while the immobiliser reads the chip | None, the chip takes its power from the car as it is read | The blade cut and the chip programmed to the immobiliser |
| Remote key | Buttons on the head of the key, with the blade as the backup | The blade is turned in the ignition lock while the immobiliser reads the chip | One, for the remote buttons | The blade cut, the chip programmed and the remote matched to the car |
| Flip key | Buttons on the case, with the folding blade as the backup | The folding blade is turned in the ignition lock while the immobiliser reads the chip | One, for the remote buttons | The same three stages as a remote key, in a folding case |
| Smart key | The car senses the key nearby and unlocks at the handle, with the buttons and an emergency blade as backups | A start button is pressed with the key inside the car | One, for the buttons and the keyless functions | The fob programmed to the car and the emergency blade cut |
The last column matters when a key is lost or a spare is wanted. A key with more parts takes more stages of work, and a quote is agreed before work begins.
Not sure which type of key your car uses? The key type is confirmed on the call to Matt.
Call Matt on 0116 442 2084Which Type of Car Key Do You Have?
Four checks with the key in your hand show which type of car key you have, and the first three take no tools and no knowledge of the car.
- Look for buttons. A key with no buttons is a mechanical key or a transponder key. A key with buttons is a remote key, a flip key or a smart key.
- Look at the blade. A blade fixed to the head points to a remote key or one of the two types with no buttons. A blade that folds into the case is a flip key. A fob with no blade showing is a smart key, and its emergency blade slides out of the case.
- Look at how the engine starts. A key turned in an ignition lock is a mechanical, transponder, remote or flip key. A start button pressed with the key still in a pocket is the sign of a smart key.
- Settle the last doubt with the handbook. A key with no buttons and a plastic head is a transponder key on a car with an immobiliser, and the handbook of the car states whether an immobiliser is fitted.
Where the checks leave a doubt, the make, the model, the year and the registration identify the car, and the key type is confirmed on the call.
Why Does a Newly Cut Key Not Start Every Car?
A newly cut key does not start a car with an immobiliser until its transponder chip is programmed, because the immobiliser lets the engine run only for a chip it recognises.
Cutting and programming are separate stages of key work. Cutting shapes the blade so that it turns the locks. Programming introduces the chip to the car so that the immobiliser accepts it.
A key that is cut and not programmed opens the door and turns in the ignition, and the engine stays off. The stage is set out in full under what car key programming is.
A mechanical key is the one type that is finished at the cutting stage, because the car it belongs to has no chip to read.
How Do Car Key Blades Differ?
Three blade forms are found on car keys, the edge cut blade, the laser cut blade and the emergency blade.
- Edge cut blade. An edge cut blade has its cuts along one or both outer edges, like a house key. It is the older form and appears on mechanical keys and on many transponder keys.
- Laser cut blade. A laser cut blade is thicker, and its cuts run as a winding track along the flat face of the blade. It appears on many remote keys and flip keys.
- Emergency blade. An emergency blade is the short blade stored inside a smart key. It opens the driver door when the battery of the fob or of the car is flat.
The blade form is separate from the key type. A flip key carries an edge cut or a laser cut blade according to the car.
What Else Depends on the Type of Key?
Five questions sit beside the key type itself, and each one belongs to a page or a decision of its own.
How Does Cutting a Car Key Differ From Programming It?
Cutting a car key works on the metal, while programming works on the electronics. Cutting gives the blade the shape that turns the locks of one car, and programming makes the chip or the fob known to that car.
A mechanical key takes cutting alone. A transponder, remote or flip key takes both, and a smart key takes programming with a cut emergency blade. The methods and the accuracy of the cut are explained in the guide to how car key cutting works. The cutting stage, the blade profiles and the methods are set out under car key cutting in Leicester.
Where Does a High Security Key Fit?
A high security key is not a sixth type. The term describes the features that make a key harder to copy, a laser cut blade and an encrypted chip among them, and those features appear on transponder, remote, flip and smart keys alike. The features themselves are explained under high security car keys.
How Does a Smart Key Relate to Keyless Entry?
A smart key is the part in your pocket, and keyless entry is the system in the car that senses it. Cars with keyless entry unlock automatically when the key comes within a short distance of the car.
That convenience carries a known weakness. Thatcham Research states that a car with passive keyless entry and start is open to a theft method called the relay attack, and its guidance on car security lists the defences. How the system works, and how it differs from a remote key, is covered under keyless entry systems.
What About a Used Car Bought With One Key?
A used car bought with one key leaves a second key unaccounted for, whatever the key type. Police advice on preventing vehicle theft is to reprogramme the keys after buying a second hand car.
When that work is done, missing electronic keys are removed from the immobiliser memory where the vehicle supports it. A mechanical blade still turns a physical lock unless that lock is changed or rekeyed.
Is a Phone or a Card a Car Key?
A phone or a key card replaces the key fob on some newer cars, and the maker of the car issues and manages that access. It sits outside the five key types because no blade is cut and no fob is supplied.
Car keys are cut and programmed at the vehicle in Leicester and across Leicestershire for supported models, and the phone is answered 24 hours a day.
Frequently Asked Questions
Does every car key have a chip?
No, a mechanical key has no chip, while transponder, remote, flip and smart keys each carry one.
A car with an immobiliser reads the chip before the engine runs, so each key made for that car carries a chip programmed to it.
Is a key fob the same as a smart key?
No, a key fob is any key with remote buttons, while a smart key is the type that unlocks and starts the car without leaving a pocket.
A remote key and a flip key are both key fobs in everyday speech. A fob that goes into an ignition lock is one of those two.
Does a transponder key have a battery?
No, a transponder chip has no battery and takes its power from the car as it is read.
A battery inside a key powers the remote buttons or the keyless functions. A remote key with a flat battery still starts the car in the ignition.
Does a smart key have a metal blade?
Yes, a smart key carries an emergency blade inside the fob on most models.
The blade opens the driver door when the battery of the fob is flat. The handbook of the car shows where the blade and the door lock are found.
Is a flip key different from a remote key inside?
No, a flip key holds the same chip, remote transmitter and battery as a remote key, and only the folding blade differs.
A folding blade that no longer locks in place is a fault of the case and leaves the electronics untouched.
Which type of car key costs more to replace?
A car key costs more to replace as the number of parts in the key and the stages of work rise, and a quote is agreed before work begins.
The make, the model, the year and whether a working key still exists move the figure as well. No price list is published.
What is checked before a new car key is made?
Identity and authority to request the work are checked before a new car key is made, whatever the key type.
The V5C vehicle registration certificate, which names the registered keeper, and photo identification are common examples, and what applies is confirmed on the call.