Rekeying vs Changing Locks: Key Differences

You just got the keys to your new home. It’s an exciting moment, but a nagging question lingers: who else has a copy? The previous owner, their contractors, their dog walker—it’s impossible to know. Taking steps to improve your home security after moving in is the only way to get real peace of mind, whether you’re a homeowner or figuring out how to secure a home after a tenant leaves.

Your first instinct might be to call a locksmith and replace every lock on your doors. While that is certainly one solution, there’s often a simpler and much more affordable option. Many people use the terms “rekeying” and “changing the locks” as if they mean the same thing, but they are fundamentally different processes with different costs.

Making the right choice comes down to a simple distinction: are you changing the password or the entire device? One option alters the inside of your existing lock so only a new key works, while the other replaces the hardware completely. Understanding these differences is key to making the smartest choice for your security and your wallet.

What ‘Changing a Lock’ Actually Means (It’s a Full Hardware Replacement)

When you hear the phrase “changing locks,” you’re probably picturing exactly what it is: removing the entire lock from your door and installing a brand-new one. This includes the knob or handle, the deadbolt, and all the internal components. Think of it like replacing your old phone with a new model—you’re getting all new hardware, not just changing the password. The old lock and its keys are gone for good, replaced by a fresh set.

This is your go-to option when you want to change the style of your door hardware—perhaps updating from dated brass to a modern matte black finish. It’s also the only solution if your current lock is broken, rusted, or if you’re interested in upgrading to high-security locks or a smart lock system. If the hardware itself is the problem, a full replacement is the answer.

Because it involves a full hardware swap, changing locks is typically the more time-consuming and expensive choice. The process requires uninstalling the old unit before fitting the new one. But what if your lock works perfectly fine, and you just need to make sure old keys no longer work? For that, there’s a much simpler and more affordable alternative.

What Is Rekeying? The ‘Password Change’ for Your Front Door

That simpler alternative is called rekeying. If changing a lock is like getting a whole new phone, rekeying is like changing the password to your email account. You keep the same account (your existing lock hardware), but the old password (your old key) is instantly blocked, and a new one is required for access. It’s a fast, elegant solution that restores your home’s security without altering its appearance.

So, what does rekeying a lock mean in practice? Instead of replacing the knob and deadbolt, a locksmith will service the small lock cylinder—the part your key slides into. Inside that cylinder is a set of tiny pins, arranged in a unique pattern that matches only your key. A locksmith can take the cylinder apart and replace these pins with a new set, effectively giving the lock a new “combination” that corresponds to a brand-new key.

The moment this process is complete, any old keys that are floating around—whether with a previous tenant, a contractor, or a former dog walker—are rendered completely useless. Your lock looks identical on the outside, but it is now secure against anyone who might have a copy of the old key.

Because it’s much faster and doesn’t require you to purchase new hardware, rekeying is often the most cost-effective way to secure your doors. It delivers the same peace of mind as a full replacement when your current locks are still in good working order. This makes it the ideal choice in several common scenarios.

When to Rekey Your Locks: The Smart & Secure Choice in 4 Common Scenarios

Knowing that rekeying is an option opens up a fast, budget-friendly way to secure your home. The rule of thumb is simple: if your lock hardware is in good shape but you can’t be sure who holds a key, rekeying is almost always your best move. It delivers the exact same security outcome—rendering old keys useless—as a full replacement, but for a fraction of the cost and time. This makes it the clear winner in several everyday situations.

Choosing to rekey is the most logical and cost-effective solution when:

• You just moved into a new home or apartment. You have no way of knowing who the previous residents gave a key to. Rekeying on day one provides immediate peace of mind.
• You lost a set of house keys. Instead of worrying if your keys will fall into the wrong hands, a quick rekeying appointment makes the lost set completely obsolete.
• A tenant, roommate, or contractor has left. Even if they return their key, you can never be certain they didn’t make a copy. Rekeying is a standard security step for landlords and anyone sharing their space.
• You want all your home’s locks to work with a single key. If you’re tired of fumbling through a bulky keychain, a locksmith can rekey multiple locks to match a single new key. This process, called keying your locks alike, is a huge convenience upgrade.

While rekeying is a powerful tool for restoring security to a perfectly good lock, it can’t fix a physical problem. If your lock is old, damaged, or you simply want a different style, you’ll need to consider a full replacement.

Why You Must Change Your Locks in These 3 Situations

Sometimes, giving your lock a new “password” by rekeying it just isn’t enough. If the lock itself is the source of the problem—or if you want features your current hardware doesn’t have—a full replacement is the only practical solution. Think of it this way: rekeying fixes a key and access problem, while changing the lock fixes a hardware problem. It’s the right call when the physical mechanism needs a complete overhaul.

A full lock change is the non-negotiable choice in these key scenarios:

• The lock is broken, rusted, or malfunctioning. If your key sticks constantly, the knob wiggles excessively, or the deadbolt struggles to engage, the lock’s internal parts are likely failing. At this point, a rekey won’t fix the unreliability, and changing the lock is essential for your security.
• You want to update your home’s style. Do your old brass knobs clash with your new, modern front door? The only way to get a new color, finish, or design for your door hardware is to replace it entirely.
• You’re ready for a security or technology upgrade. A basic lock, even when rekeyed, is still a basic lock. For better protection, you must change the hardware to get features like pick-resistant high-security locks. The same is true if you want the convenience of smart locks you can control with your phone.

Is It Cheaper to Rekey or Replace Locks? A Realistic Cost Breakdown

For most people, the decision between rekeying and replacing comes down to one crucial factor: cost. In this head-to-head comparison, rekeying is the undisputed winner for your wallet. Choosing to rekey your existing locks instead of replacing them entirely can save you anywhere from 50% to 70% on your final bill. This significant saving comes from avoiding the single biggest variable in any lock-related job: the cost of new hardware.

The total cost to have a locksmith change locks is made of three parts. First is the service call fee, a standard charge just for the professional to come to your home. Second is the labor for the installation. Third, and most importantly, is the hardware cost—the price of the new lock itself. A basic deadbolt might only be $30, but a stylish, high-security smart lock could easily run over $250. This is where the price can quickly escalate.

In contrast, the cost of rekeying is much more predictable. You still pay the locksmith’s service call fee and for their labor, but you completely eliminate the hardware expense. You’re simply paying for a skilled technician to reconfigure the lock you already own. Because you aren’t buying a brand-new product, rekeying offers substantial savings while achieving the same level of security. This makes it the go-to choice for new homeowners and anyone on a budget.

DIY Rekeying Kits vs. a Locksmith: Is the Small Savings Worth the Risk?

After learning that rekeying is cheaper than a full replacement, your next thought might be, “Can I just do it myself?” A quick search reveals DIY lock rekeying kits, promising a fast and cheap solution. These kits, available at most hardware stores, contain the new pins and special tools needed to change the lock’s internal combination. For a handy individual, it seems like the perfect way to save on a locksmith’s service fee.

However, the convenience of these kits comes with significant limitations. The first major hurdle is that they are brand-specific; a kit for a Kwikset lock won’t work on a Schlage lock, and vice versa. If your home has a mix of brands, you’d need to buy multiple kits, quickly diminishing any savings. This is a common obstacle that sends many well-intentioned DIYers back to square one.

Beyond brand compatibility, the rekeying process itself is extremely delicate. Inside your lock are tiny, color-coded pins that must be placed in a precise order. One slip, and you could drop a spring no bigger than a grain of rice, permanently damaging the lock. Worse, you could rekey it incorrectly, creating a “false security” scenario. The lock might seem to work, but its internal flaw could make it incredibly easy for someone to bypass, leaving your home vulnerable.

The comparison between a DIY kit and a locksmith comes down to weighing a small financial saving against a major security risk. A professional locksmith rekeys locks every day, guaranteeing the job is done correctly and your home is secure. For the peace of mind that comes with knowing your locks work exactly as they should, hiring a qualified professional is almost always the smarter investment.

Your Final Checklist: The Right Choice for Your Locks in Under 60 Seconds

What once seemed like a confusing home security task is now a clear choice. You’re equipped to decide exactly what your home needs, saving you time, money, and stress. To lock in your decision, ask yourself: is my lock hardware in good shape, and is my main goal simply to control who has a key?

• CHOOSE TO REKEY IF: Your locks are in good condition AND your only goal is to make old keys stop working. This is the budget-friendly choice for security control.
• CHOOSE TO CHANGE LOCKS IF: Your locks are broken/old, you want a new style, OR you want to upgrade to a smart or high-security lock. This is the choice for hardware upgrades.

With this knowledge, you can act with confidence. You now have everything you need to call a local locksmith and tell them exactly what service you require.