Lost Your Car Keys? What to Do Next

Losing the only key to your car can stop an ordinary day cold. The good news is that a lost key is a problem with a clear solution, and the steps are the same whether it went missing at home, at work or somewhere in between.

Step 1: Search in a smart order

Start with the last place you are sure you had the key, and work backward through your day. Look where keys really end up, not only where they are supposed to be.

• Coat and jacket pockets, including the ones you wore yesterday.
• Bags, backpacks, gym bags and grocery bags.
• Under and between the car seats, if the car is unlocked.
• Still in the front door lock at home, or on a table by the door.
• Any place you stopped: a store, a restaurant, a friend's house. Call and ask whether a key was turned in.

Step 2: Make sure the car is secure

If the car is parked somewhere public, check that it is locked. If the key went missing together with something that shows your address, such as a wallet or a bag, take that seriously: someone may now have a key to your car and know where it is parked at night.

If house keys were on the same ring, the locks at home matter just as much. Our guide on what to do after a break-in covers changing them.

Step 3: Find the spare, or get ready for a new key

If there is a spare key somewhere, that is the simplest fix. Remember that the spare is now your only key, so plan to have a second one made soon.

With no spare, the car needs a new key made for it. These details make that straightforward:

• The year, make and model of the car.
• The vehicle identification number (VIN). It is printed on the registration and the insurance card, and on a small plate at the base of the windshield on the driver's side.
• Proof that the car is yours. A photo ID and the registration or the title.

Step 4: Know what kind of key you had

Many car keys, even plain-looking ones, carry a small chip in the head that the car has to recognize before the engine will start. That is why a key cut from a blank at a hardware counter can open the door and still not start the car.

• Plain metal key. A cut blade and nothing else. Mostly older cars.
• Transponder key. Looks plain but has a chip in the head. It has to be cut and programmed.
• Remote key or key fob. Buttons for the locks plus a chip, with a blade that is fixed, folds out, or hides inside.
• Smart key. Stays in your pocket or bag while you start the car with a button.

Not sure which one you had? Our guide to transponder keys, fobs and smart keys explains how to tell them apart.

Step 5: Have the new key made at the car

A mobile locksmith can cut and program a replacement key where the car is parked, so the car can stay where it is. On the phone, give the year, make and model, and say whether you still have any working key for it.

What to expect

You will be asked for ID and proof of ownership before any key is made. Treat that as a good sign: it is what stops a stranger from getting a key to your car.

Once the new key works, think about a second one right away. Being down to a single key is exactly how this started.

How to avoid losing the only key again

• Keep a spare at home, in one place you will remember, and not inside the car.
• Give keys a home. A hook or a bowl by the door ends most searches before they start.
• Make the key easy to spot. A bright key ring or a larger tag is harder to lose at the bottom of a bag.
• Add a tracking tag. A small tracker on the key ring can show where the keys were last seen.