How to Copy a Key Fob

Key fobs can add an extra layer of security to your home and make it easier to unlock your car with your hands full. Having a spare available can come in handy. Ordering a replacement from the manufacturer can cost as much as $500, so it's worth exploring some alternative methods before shelling out.

Knowing how to copy a key fob can save you time and money next time you need a spare for your car or home.

Knowing how to copy a key fob can be useful if you have a fob from an old car hanging around and want to use it as a spare for your new vehicle. You might be able to copy your key fob yourself if the same manufacturer made both cars. Or, you may be able to find a replacement fob for purchase online.

The method for pairing a key fob with your car varies widely across brands and often entails turning the ignition several times and pressing certain fob buttons to activate the pairing function.

Check your car's user manual to see if it contains instructions for pairing an old key fob. Alternatively, you could try searching or posting on an automotive chat board online to see if anyone knows how to reprogram your fob. Bear in mind that most manufacturers limit the number of key fobs you can pair with a vehicle, most often to a maximum of four fobs.

If your car doesn't enable fob copying or the key fobs are from different brands, you still have a few options available. The methods below will also work for copying some car key fobs, although you'll need to request a copy from the manufacturer if you have an encrypted fob.

How Do You Copy Other Key Fob Types?

There are several methods for copying a key fob. Which one is the best option depends on your budget, how quickly you need a new fob and the type of key fob you have.

1. Visit a Locksmith or Hardware Store

Many locksmiths and hardware stores have the equipment and knowledge to copy key fobs, providing they're unencrypted. Bear in mind that most reputable companies will only copy fobs that access private residences or cars to stop people from copying fobs that might allow access to restricted areas.

Before heading to the store, you can call in advance to ask if the technician can copy your fob brand and type to save yourself a wasted journey. You may need to provide certain information, including the fob's serial number.

2. Use an Online Copying Service

Numerous online businesses offer fob-copying services, and some operate brick-and-mortar kiosks in certain areas. You'll need to provide proof of your identity and ownership of your key fob, as companies are legally obligated to obtain this data to prevent criminals from copying fobs that aren't theirs.

Depending on your fob type, the company may be able to copy it remotely without physical access to the fob. You can find out if your fob is suitable for remote copying by providing the serial number. If it isn't, you'll need to mail your key fob to the company for copying. Using a fob copying service won't be suitable if you have an encrypted key fob.

3. Use an RFID Writer

RFID writers are handheld devices that can copy unencrypted 125kHz (kilohertz) fobs and key cards. An RFID writer could be a worthwhile investment if you need to copy multiple fobs or want the option of creating more copies in the future. You can purchase an RFID writer online or from certain hardware stores, and there are affordable models available.

You'll usually need to purchase blank fobs or key cards to make copies with an RFID writer. However, some models come with a set of blank fobs so you can use them immediately.

How to use an RFID writer varies across brands, but it doesn't usually require any specialist knowledge. It's often as simple as pointing the writer at the existing fob and clicking the “read” button. You can then point the device at the blank fob and click the “write” button to program the new fob.

4. Call the Manufacturer

Many modern key fobs are encrypted to prevent unauthorized access to your property or vehicle. While this helps improve your home's security, it prevents even the rightful owner from producing copies themselves.

In this situation, your only option is to call the manufacturer and ask them to send you an extra fob. Providing the serial or model number can help the manufacturer identify your key fob and produce a copy. You may need to prove your identity. Ordering an additional fob from the manufacturer is generally more expensive than other methods, especially if you have a fob that performs multiple functions.