Copying a key means making a duplicate that works in the same lock

When you copy a key, a locksmith or key-cutting machine creates a new key that fits and operates the same lock as your original. The copy is made by reading the cuts and grooves on your original key — either by hand with a mechanical cutter or by scanning it with a machine — and reproducing those exact patterns on a blank key. A properly copied key will turn the lock, unlock doors, and function identically to the original.

Most people copy keys at hardware stores, locksmiths, or key-cutting kiosks in supermarkets. The process takes a few minutes and costs between $2 and $10 per key, depending on the key type and where you go. Some keys — like those for cars, mailboxes, or security systems — cannot be copied without proof of ownership or authorization, and attempting to do so is illegal.

Key Takeaways

  • A copied key is a new key cut to match the exact grooves and cuts of your original, so it works in the same lock.
  • Standard house and office keys can be copied at hardware stores, locksmiths, or supermarket kiosks in minutes for a few dollars.
  • Restricted keys — including most car keys, mailbox keys, and security system keys — are legally protected and cannot be copied without proof you own the lock.
  • A bad copy may turn partway in the lock but not fully operate it, which usually means the cuts were not deep or precise enough.
  • Keeping a spare copy in a safe place protects you if you lose your original key or get locked out.

Where to get a key copied

Hardware stores like Home Depot, Lowe's, and Ace Hardware have key-cutting machines staffed by employees. You bring your original key, hand it to the staff member, and they insert it into the machine alongside a blank key. The machine traces the cuts on your original and reproduces them on the blank. Most stores cut keys while you wait, usually in under five minutes.

Locksmiths offer the same service and are useful if you have an unusual key, a damaged original, or a key that hardware stores refuse to cut. They can also copy keys from a photo or description if you do not have the original with you, though this costs more and is less reliable. Supermarket kiosks — found in many grocery stores and pharmacies — work the same way as hardware store machines and are often cheaper, but they may have fewer blank key options available.

Some people copy keys at home using a file and a blank key, but this requires skill and produces inconsistent results. Unless you have locksmithing experience, a professional copy is worth the small cost because a poorly cut key can jam in the lock or break inside it.

Why some keys cannot be copied

Restricted keys are protected by law and cannot be copied without authorization. Most car keys fall into this category — dealerships and locksmiths will not cut a copy without proof that you own the vehicle. The same applies to mailbox keys (which the postal service controls), security system keys, and keys to rental properties or commercial buildings.

The restriction exists because copying these keys without permission could allow someone to access a vehicle, mailbox, or building they do not own. If you need a copy of a restricted key, you must contact the organization that issued it — your car dealership, the post office, your landlord, or your employer — and provide proof of ownership or authorization.

What happens when a key copy does not work

A copied key that does not work usually means the cuts were not deep enough, not in the right places, or not precise enough to match the lock's pins. The key may slide into the lock but refuse to turn, or it may turn partway and then stick. This happens most often with older keys that are worn down, keys with unusual shapes, or copies made on low-quality machines.

If your copy does not work, take both the original and the copy back to where you had it cut. Most locksmiths and hardware stores will re-cut it for free or for a small fee. If the original key is worn or damaged, a locksmith can sometimes create a copy by examining the lock itself rather than the key, though this is more expensive.

The difference between copying and rekeying

Copying a key and rekeying a lock are two different things. Copying makes a duplicate of an existing key so multiple people can use the same lock. Rekeying changes the lock's internal pins so that old keys no longer work and new keys do. Rekeying is what you do when you move into a rental apartment and want to make sure the previous tenant cannot enter, or when you lose a key and want to prevent whoever finds it from using it.

Rekeying costs more than copying — usually $50 to $200 per lock — because it requires taking the lock apart and replacing internal parts. Copying is just making a duplicate and costs a few dollars. If you want multiple people to have access to the same lock, copying is the right choice. If you want to prevent someone from using an old key, rekeying is what you need.

Why you should keep a spare copy

Keeping a spare copy of your house key, office key, or car key in a safe place protects you if you lose the original or get locked out. A spare at home — stored somewhere find but not hidden so well that you cannot find it — means you can get back inside without calling a locksmith. A spare at work or with a trusted friend or family member means you have a backup if your original is lost or stolen.

Do not hide a spare key under a doormat, in a planter, or above the door frame. These are the first places someone will look if they are trying to break in. Instead, keep it in a locked drawer, a safe, or with someone you trust. If you are renting, check your lease before making copies — some landlords restrict how many keys tenants can have.

Frequently Asked Questions

Can I copy a key if I do not have the original with me?

A locksmith can copy a key from a photo or description, but the result is less reliable than copying from the original. Some locksmiths will also create a key by examining the lock itself if the original is lost. Both methods cost more than a standard copy and may require a second visit if the first attempt does not work.

Is it illegal to copy someone else's key?

Yes. Copying a key without the owner's permission is illegal and can be charged as theft or burglary. Most locksmiths and hardware stores will ask to see your original key before copying it, partly to prevent this. If someone copies your key without permission, contact the police and consider rekeying the lock.

Why did my copied key break inside the lock?

A key breaks inside a lock when it is too weak, too thin, or cut incorrectly. Cheap blanks and low-quality machines produce weaker copies. If a key breaks inside your lock, do not try to remove it yourself — call a locksmith, who has tools to extract it without damaging the lock mechanism.

How long does a copied key last?

A well-made copy lasts as long as your original key — usually years or decades. Keys wear down slowly from repeated use, and a copy wears at the same rate as the original. If your copy stops working before the original does, it was probably cut poorly and should be re-cut.

Can I copy a key at a supermarket kiosk if the store is closed?

No. Supermarket key-cutting kiosks are only available during store hours and are usually staffed by employees. Some hardware stores have 24-hour locations, but key-cutting service is only available during business hours. If you need a key copied outside normal hours, call a 24-hour locksmith.