Used cars are frequently sold with a single key. Sometimes the second was lost years ago; sometimes the seller kept it; sometimes a dealership never received it. Whatever the reason, buying a car with one key leaves you with two problems, and most people only know about the first.
Problem one: you are one dropped keyring from an expensive week
One key means every loss is an all-keys-lost event. On a domestic vehicle that is a meaningful jump in cost. On a European vehicle it is potentially several hundred dollars and three hours.
Adding a spare while you still have a working key is fast, cheap, and can be done in a workplace parking lot. It is the cheapest insurance available to a car owner and it costs a fraction of what it prevents.
Problem two: somebody else may still have a key
This is the one people do not think about, and it deserves more attention than it gets.
You cannot know how many keys exist for a car you did not buy new. The previous owner may have kept a spare. A family member may have one. A dealership may have cut one. A valet or a mechanic may have copied one years ago. The seller may be entirely honest and still not know.
For most people this is a low risk that never materialises. But if the car was bought from a private seller you cannot vouch for, from an auction, or after a repossession or estate sale, it is worth closing off.
Do both at once
The efficient move is a single visit that adds your spare and wipes everything else. You end up knowing exactly how many working keys exist for your car — two, both in your possession — which is a genuinely nice thing to know.
While you're at it
- Check the emergency blade. If your smart key has a hidden mechanical blade, confirm it actually opens the driver's door. On used cars it is sometimes the wrong blade or a worn one.
- Replace the fob battery. You have no idea how old it is. It is a few dollars and it resets the clock.
- Check the door keypad code, if your vehicle has one. Ford in particular — the previous owner's code may still work, and a factory code can usually be retrieved or reset.
- Test the valet key, if there is one. Some cars ship with a restricted key that opens doors but not the trunk or glovebox.
What it costs
A spare on most domestic and Asian vehicles runs $95 to $300. European proximity keys run $240 to $520. Erasing previously issued keys during the same visit is included in our pricing rather than charged separately, because it takes minutes once the session is open.
Compare that to all-keys-lost — $220 to $480 domestic, $450 to $950 European — and the arithmetic makes itself.
Want this checked on your actual car?
Guides only get you so far. Call with your year, make, and model and we’ll tell you what applies to your vehicle specifically — including when the answer costs you nothing.