Key Duplication: How It Works, Who Does It, and What You Need to Know

When you need a spare key, you’re not just asking for a copy—you’re asking for key duplication, the process of making an exact replica of a physical key using a machine that matches the original cuts. Also known as key copying, it’s one of the most common services offered by locksmiths, trained professionals who install, repair, and replicate locks and keys. Whether it’s for your house, car, or office, a duplicated key should work just like the original—no guesswork, no jams, no extra trips to the hardware store.

Not all keys are easy to copy. Standard house keys? Simple. High-security keys with patented designs? Not so much. Many modern keys have chips, side-milling, or special materials that require licensed equipment and authorization. That’s where key cutting, the mechanical process of shaping a blank key to match the original’s grooves and depths comes in. A good locksmith doesn’t just run a key through a machine—they check the original for wear, match the bitting precisely, and test the new key before handing it over. Skip the cheap key kiosks at gas stations if you want reliability. Most failed duplicates come from untrained operators using outdated machines.

Car keys add another layer. Modern vehicles use transponder keys with embedded chips that must be programmed to the car’s computer. Just copying the physical shape won’t start the engine. You’ll need a professional with diagnostic tools and access to manufacturer codes. Some people try to save money by buying blank keys online, but without proper programming, it’s just a fancy paperweight. And if you’ve lost your only key? That’s when you really see why locksmith services, emergency and routine solutions for lock and key issues, including rekeying and lock replacement matter. A good locksmith can often make a new key from the lock itself—even without the original.

What you pay depends on where you go, what kind of key it is, and how fast you need it. A basic house key might cost under $10. A car key with a chip? Could be $50 to $150. Some places charge extra for after-hours service or mobile calls. Always ask for a quote upfront. And remember—just because a key looks copied doesn’t mean it’s legal. Certain keys, like those for government buildings or high-security systems, are protected by law. Unauthorized duplication can get you fined or worse.

Here’s what most people don’t realize: a duplicated key isn’t just a backup. It’s a security decision. Too many copies floating around? That’s a risk. Not enough? You’re locked out. The smart move is to keep one original, make one trusted spare, and store the rest securely—or better yet, use a key management system. If you’re renting, check your lease. Some landlords require you to return all copies when you move out.

Below, you’ll find real guides from people who’ve dealt with key issues—whether it’s figuring out why a copied key won’t turn, learning how to tell if a locksmith is legit, or understanding why your car won’t start even with a perfect copy. No fluff. Just what works.