Short answer: No federal or California law makes a seller hand over two keys, and many used cars arrive with one. Add a second while it works: chip keys run $125 to $199 and smart keys $229 to $399. Lose the only key and it is $60 more, or a tow and a dealer bill. Have stray keys erased.
The car checked out, the papers were signed, and one key came across the desk. Or a private seller said the spare went missing years ago. Either way, you own a car with no backup and maybe a working key you have never seen.
Below: why one key is so common, what to put in the contract if you have not signed, what a second key runs with us against the dealer, and the step that is easy to skip, erasing keys you cannot account for from the car's memory. Both jobs fit in one visit.
Why so many used cars come with only one key
Nothing requires a second key. No federal or California law obliges a seller, whether a dealer or a private party, to hand over two, according to a legal explainer published in January 2026, and a lawyer directory quoted in news coverage says the law does not regulate it. The number of keys you drive away with is whatever the deal says.
Keys also drift away as a car passes through earlier owners: one lost in a move, one kept by a former partner. A replacement chip key at a dealer runs $230 to $380, and a seller about to hand the car over has little reason to pay that.
Not signed yet: write two working keys into the contract
The fix costs nothing if you catch it before signing: have the words two working keys written into the purchase contract. Working is the word that carries weight. A key that opens the doors yet leaves the engine dead does not qualify, and neither does a fob that belonged to some other car. Test both on the lot, engine and buttons, before you sign.
If the seller refuses the line, the second key becomes your expense, so put its price into the negotiation. Dealer figures run $230 to $380 on a chip key and $400 to $750 on a smart key; ours follow below.
Already signed: the second key belongs in week one
While one key still works, the new one is an add: the car already accepts a key and simply registers another beside it. You pay the key price alone, a chip key $125 to $199 or a smart key $229 to $399, drive included, and the key, any remote buttons and the programming are covered for a year.
Lose that key before the spare exists and you are into a lost-keys job: the spare price plus $60, because there is no key to work from. The blade is cut by a code looked up from the VIN, and the immobilizer is set up fresh. State law (Penal Code 466.6) requires a work order recording your ID and the registration for any key not made by copying, so keep the title or registration and your ID together.
Recent buyers can hit a snag there: until the DMV finishes the transfer, the registration in the glovebox may still carry the seller's name. Say so on the phone, and the papers question gets settled while you still have a key to drive with.
At a dealer, a car with no key left rides in on a $125 to $200 flatbed, then may wait one to three days while the store orders the key.
A key the last owner kept can still start the car
Your car's immobilizer keeps a roster of the keys it accepts, and the sale left that roster as it was. A spare the last owner left in a kitchen drawer, or one lent to a relative years ago, may still start the engine. The one key in your hand says nothing about how many others the car still answers to.
The fix rides along with the new key. When keys are programmed, the ones not at the car can be removed from its memory, so a key you do not hold stops starting the engine. Bring every key you plan to keep, since a key left at home is the kind that gets removed, and ask for the erase when you call so it is in the quote.
Know where that stops. Erasing a key keeps it from starting the car. It does not change the door lock, so the metal blade of a key you never got back still fits the lock it was cut for.
Ford, Toyota and other makes with their own rules
Some makes let an owner add a key without a tool, but only once two working keys exist. Ford is one of them: with two, an owner can add a third on their own; with one, every new key needs a programmer at the car. On a one-key Ford, the second key does double duty, covering a loss and letting you add a third later without a tool.
For a 2022 to 2024 Toyota, make one phone call before booking anyone. Toyota delivered some of those models with a single smart key and offered the second for a nominal one cent through its Second Key Delivery Program, described in a notice on file with NHTSA. Ask a Toyota dealer whether your VIN qualifies. If it does, that penny key beats every figure on this site.
The first week with a one-key car
Count and test. Start the engine with every key you were given, press each button, and try the blade in the driver's door. Then send a photo of that key and the car's year, make and model; the quote comes back before the van leaves.
While the VIN is handy, run it through nhtsa.gov/recalls. A franchised dealer repairs open recalls free, and a used car can carry one its previous owner never had done.
Book the second key and the erase as one visit, papers within reach. The new spare lives indoors where every driver can find it, not on the ring with the first key, and the car is back to the two keys it should have had at signing.