Lost Your Cat Key? Here’s What to Do Next

What is a cat key and why is it important?

A cat key is an electronic key that provides access to your car and controls various functions. It is often integrated into a key fob or smart key system. There are several reasons why cat keys are important:

Definition of a cat key: A cat key is an electronic access device that unlocks the doors and starts the ignition of your vehicle. It contains a radio frequency transponder that communicates with your car’s engine immobilizer system. When you insert the key in the ignition or press the key fob, it sends a signal to a receiver in the car that verifies the key is authorized to start the engine.

Reasons it provides access to the car: The cat key allows you to unlock the doors and trunk of your car. Without it, you cannot get into your vehicle. It is the primary means of access and control over your automobile.

Controls key functions: Modern cat keys do more than just start the engine. They can control power locks, alarms, remotes start, and keyless access. The chips in cat keys programmed with your vehicle’s specific code to enable all these functions.

Realize the key is lost

The first step when you lose your car key is to notice it is missing. Check your pockets, bag, jewelry box, nightstand, or any other common location where you may have placed the key. Thoroughly search areas you frequented that day or the night before. Confirm the key cannot be found in any expected places before concluding it is truly lost.

According to AAA, when realizing your key is lost, it’s important to retrace your steps and thoroughly check where you last remember having it. Don’t assume it’s lost until confirming it’s not somewhere obvious you may have misplaced it.

Temporary Workarounds

If you’ve lost your car key, there are a few temporary workarounds to regain access to your vehicle while you work on getting a replacement key made:

Call a locksmith. A professional automotive locksmith can make a duplicate key on the spot if you have a spare key code or can retrieve the key code from the vehicle’s computer system. This allows you to get back on the road quickly, often within an hour. Locksmith services tend to be more affordable than getting a replacement key from the dealership.

Use a spare key. If you have a spare key at home, you can use that to temporarily access your car. Just be sure to keep it in a safe place until you get a replacement made.

Have the key replaced. You’ll need to get the lost key replaced for long-term access to the vehicle. The options include having the dealer program a new smart key, getting a locksmith to cut and program a duplicate, or finding an automotive locksmith to make a new key from scratch. Replacing the key as soon as possible is recommended.

Long-term solutions

If you’ve exhausted all temporary options and still can’t find your lost cat key, you’ll likely need a replacement key. There are a few long-term solutions to get a new key made:

Get a replacement key

You can get a replacement key made by your dealership or a locksmith. The dealership will be able to cut and program a new key using your VIN number, but this can be expensive. A mobile locksmith can come to your location and make a replacement key on the spot, which is often faster and cheaper than the dealership. According to AAA, an automotive locksmith can make a key replacement for most vehicle models.

Program a new key

If you have an existing working key, you can buy a blank key and have it programmed to work with your vehicle. This may require special equipment, so you’ll need to work with your dealership or locksmith. Programming a new key is typically cheaper than getting a fully replacement key. According to GEICO, locksmiths can program new keys for most, but not all, vehicle models.

Install new locks

As a last resort, you can choose to replace your vehicle’s entire lock cylinder and install new locks. This is the most expensive option, but ensures unauthorized individuals cannot use your lost key. Work with a professional locksmith or dealership to remove the old lock cylinder and install new locks properly. This will require programming all replacement and existing keys.

Costs of Replacing a Lost Key

Replacing a lost car key can be quite expensive, especially if you need to get it done quickly by a professional locksmith. There are generally three main costs associated with replacing a lost key:

Locksmith Service Charges: Hiring a locksmith to come to your location and make a replacement key can range from $50-$300 depending on factors like time/location, vehicle make/model, and any programming needed. Many charge a base service fee plus additional fees for cutting and programming new keys. According to JD Power, you could pay $50 or more just for the service call itself.

New Key Costs: The actual key blank and materials can cost $20-$50 or even more from the dealer. More complex smart key or fob designs are generally more expensive. According to Edmunds, basic keys range from $25-$60 while fobs can be $180-$400.

Immobilizer Programming: If your car has an immobilizer anti-theft system, reprogramming costs can run $50-$150 or more. The locksmith will need to connect specialized equipment to sync your new key to the vehicle immobilizer.

In total, expect to spend anywhere from $150-$500+ for a professional mobile locksmith to replace a lost car key, depending on the vehicle and type of key. Going to the dealership can be even more costly.

How to Prevent Losing Keys

There are a few simple but effective ways to avoid losing your keys in the first place:

Designate a spot for your keys – Pick a spot that you can easily access near the door, like a key hook, tray, or bowl. Make it a habit to always place your keys in that exact spot when you enter the house. This way you’ll avoid misplacing them around the home. (Source)

Attach a tracker – Get a small Bluetooth or RFID tracker that you can attach to your key ring. If you misplace your keys, you can use your phone to make the tracker beep or see its last known location. Popular options include Tile and Apple AirTags. (Source)

Make duplicates – Keep a spare set of keys somewhere safe like a locked box or with a trusted friend or family member. That way if you lose your main set, you have backups ready to go and avoid being locked out. (Source)

What to do if key is stolen

If your car key is stolen, the first step is to file a police report. Contact the local police department to file a report for your stolen car key. Be prepared to provide details about when and where you believe the key was stolen (Source).

After filing the police report, contact your car insurance company to report the stolen key. Most car insurance policies cover the cost of replacing stolen keys and reprogramming a new key. Your insurance adjuster will guide you through the claims process. Be prepared to provide your police report case number as evidence (Source).

Risks of Lost Keys

Losing your car keys can lead to some serious risks and consequences. Here are some of the main risks to be aware of:

Car Theft

One of the biggest risks is car theft. If someone finds your lost keys, they could easily unlock your car and drive away with it. According to the Letstrack, car theft is a leading risk when keys are lost or stolen.


Even if your car isn’t stolen, someone could still break in and steal valuables or vandalize the interior. Lost keys make it easy for thieves to gain access without signs of forced entry. As Nowcar notes, break-ins are a key risk.


Losing your only set of car keys means you can no longer access and start your vehicle. This can leave you stranded wherever you lost the keys, unable to drive home or get to your destination. It’s an extremely inconvenient situation.

Mobile phone apps

Mobile apps like ZUS Car Key Finder and Chipolo can help you find lost car keys using your smartphone. These apps rely on small Bluetooth tracking devices that attach to your keychain and pair with your phone.

Features of these apps include:

  • Two-way tracking to either find your keys using your phone, or find your phone using your keys
  • Notifications and alerts when keys are detected or go out of range
  • Virtual leash to warn you before keys go out of range
  • Last known location of keys shown on a map

A major advantage is the ability to access these apps remotely. As long as your keys are within Bluetooth range, you can use the app to make them beep which helps you locate them even when not physically near your keys. However, the range is limited to about 75 feet.

Limitations include reliance on batteries in the tracking device, potential for signal interference, and the need to keep the app running in the background which can drain your phone’s battery faster. These devices also won’t work if your keys are buried or hidden by objects. Overall though, key finder apps provide a helpful way to quickly locate lost keys using your smartphone.


Losing your car key can be stressful and inconvenient. The key is essential for operating your vehicle, so losing it makes driving impossible. If you have a physical key, getting a replacement made by a locksmith may be quickest and cheapest. For smart keys, you likely need to go to the dealership for reprogramming, which can be expensive. While waiting for a replacement key, consider rental cars or public transportation as workarounds. To avoid this issue, always have a spare key made and keep it in a safe place. Get a tile or key finder to help locate lost keys fast. Let your insurance company know if the key was stolen. With some effort, you can get a new key and be back on the road again.

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