A few years ago, I moved into a new apartment and wanted to make sure no one else had copies of my keys. Around the same time, my friend got locked out of his car, and he called a Car Lockout service in St. John. Watching the locksmith quickly get him back inside made me realize how important it is to trust professionals with any lock problem. I also learned that not every lock can be rekeyed. Some are old, some have special designs, and some are high-security locks that need full replacement. That day, I understood how important it is to know which locks can be rekeyed and which cannot. Here, I’ll explain which locks cannot be rekeyed and what you can do instead to keep your home safe.

What Does “Rekeyed” Mean?

When a lock is rekeyed, a locksmith changes the inside of the lock so the old key will not work anymore, and a new key can open it. The lock stays on the door; only the key mechanism is changed.

Rekeying is helpful in many situations:

• When you move into a new home

• When you lose a key

• When you want to stop someone from using an old key

Rekeying is usually cheaper than replacing the whole lock, but it only works on certain types of locks.

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Why Some Locks Cannot Be Rekeyed

Some locks are built in a way that makes rekeying impossible. The design, age, or security features of the lock can make it impossible to change the key. Here are the main types of locks that cannot be rekeyed:

1. High-Security Locks

High-security locks, like Medeco or Mul-T-Lock, are made to stop burglars from picking them. They have very complex parts inside and special key shapes. Some high-security locks cannot be rekeyed at all, and trying to do it without the right tools can break the lock. If you have one, you should talk to a certified locksmith.

2. Warded Locks

Warded locks are old locks found on antique furniture, cabinets, or old doors. They work with keys that have a special shape that matches the inside of the lock. Because they do not have pins that can be changed, warded locks cannot be rekeyed. If you need a new key, you must replace the lock.

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3. Smart or Electronic Locks

Many modern locks use electronics, like keypads, Bluetooth, or apps. These locks do not have the regular pins that can be rekeyed. To change access, you usually need to update the code, reset the system, or replace the electronic part.

4. Mortise Locks with Special Cylinders

Mortise locks are used in older homes or offices and are built inside the door. Some mortise locks can be rekeyed, but many old or custom cylinders cannot. A locksmith may need to replace the cylinder entirely to allow a new key.

5. Broken or Old Locks

Locks that are rusty, damaged, or worn out cannot be rekeyed. Rekeying only works if the pins inside the lock are working properly. If the lock is broken, it is better to replace it. Trying to rekey a broken lock can make it stop working entirely.

6. Some Padlocks

Some padlocks can be rekeyed if they have a removable cylinder. But many cheap or solid padlocks cannot. Their insides cannot be changed, so the only way to get a new key is to buy a new padlock.

Why People Try to Rekey Locks That Cannot Be Rekeyed

Many people think all locks can be rekeyed. This often wastes time and money. Some people even damage their locks by trying. Knowing which locks cannot be rekeyed helps you avoid mistakes and makes your home safer.

Read Also: Is it safe to duplicate car key? 

What to Do If Your Lock Cannot Be Rekeyed

Even if a lock cannot be rekeyed, there are ways to keep your home secure:

1. Replace the Lock or Cylinder: This is the easiest option. Installing a new lock lets you use a new key.

2. Upgrade to a High-Security or Smart Lock: If your lock is old, replacing it with a smart or high-security lock improves safety and convenience.

3. Install a Master Key System:  For businesses or apartment buildings, a master key system can control access without changing every lock.

4. Change Codes on Smart Locks:  For electronic locks, updating the access code works like rekeying.

Tips for Choosing Locks That Can Be Rekeyed

If you think you may need to change keys in the future, follow these tips:

• Pick standard pin-tumbler locks. They are easy to rekey.

• Avoid old, warded, or electronic locks if you want to rekey often.

• Ask your locksmith to make sure the lock can be rekeyed before buying it.

• Keep track of the types of locks and keys in your home.

Other Things to Think About

When deciding whether to rekey or replace a lock, remember these points:

• Security Needs: High-security areas may need special locks that cannot be rekeyed but are safer.

• Budget: Rekeying is usually cheaper than replacing the whole lock, but sometimes a replacement is worth the cost.

• Convenience: Smart locks let you change codes instead of rekeying.

• Home Age: Older homes may have locks that cannot be rekeyed.

Knowing your locks and what you need for safety will help you make smart choices for your home or business.

Summary

Rekeying is a cheap and easy way to change keys without replacing the whole lock. But it is not possible for all locks. High-security locks, warded locks, electronic locks, some mortise locks, broken locks, and some padlocks cannot be rekeyed.

Always talk to a professional locksmith. They can check your locks and tell you if they can be rekeyed. If not, they can suggest other solutions. Whether you rekey a lock or replace it, taking the right steps keeps your home safe and secure.