Rekeying vs Replacing a Lock: Which Saves More Money?
Locked out of your house? Here's exactly what to try before calling a locksmith, and when calling one is genuinely the right move.
In this guide
- Rekeying vs replacing a lock confuses a lot of people who assume they're the same thing with different names.
- Rekeying changes what key operates the lock without replacing the hardware itself, and it's usually the cheaper option.
- Replacement is genuinely necessary in certain situations where rekeying alone won't address the underlying issue.
- Moving into a new home is the single most common reason people need to choose between the two.
Moving into a new home raises an immediate, practical question that a lot of new homeowners don’t think about until they’re already holding the keys. Rekeying vs replacing a lock sounds like it might be splitting hairs, but the two are genuinely different processes with different costs, and knowing which one you actually need saves unnecessary expense.
What Rekeying Actually Involves
The internal pin mechanism of the lock is changed so a different key operates it. The physical lock hardware itself, the cylinder, the handle, the overall unit, stays exactly the same. Only the internal configuration changes, meaning old keys stop working and new ones are cut to match the reconfigured mechanism.
It’s typically faster and less expensive than full replacement. Since the existing lock hardware is reused, rekeying avoids the cost of new hardware entirely, making it the more economical option in situations where the lock itself is in good working condition.
It requires the lock to be in decent physical condition already. Rekeying addresses who can access the lock, not the mechanical condition of the lock itself, so a worn or damaged lock isn’t a good candidate for rekeying alone.
What Replacement Actually Involves
The entire lock unit is removed and a new one installed. This addresses both who can access the lock and the physical condition and security standard of the hardware itself.
It’s the appropriate choice when the existing lock is worn, damaged, or below current security standards. If a lock has been forced, has aged poorly, or simply isn’t British Standard certified, replacement addresses the underlying hardware issue that rekeying alone cannot.
It costs more than rekeying, but delivers genuinely new hardware. For a lock that needs upgrading rather than simply needing a new key configuration, this additional cost buys meaningfully better security than rekeying an outdated mechanism would provide.
When Rekeying Makes Sense
Moving into a home where the existing locks are in good condition and meet a reasonable security standard. This is the classic rekeying scenario, addressing the legitimate concern that a previous owner, or anyone they gave a key to, could still access the property, without the expense of full replacement.
Losing a set of keys without any evidence of the lock itself being compromised. Rekeying resolves the security concern of a missing key without the additional cost of replacing hardware that’s working perfectly well.
A tenant moving out, or a change in who should have access, where the lock itself remains in good condition. Landlords in particular often rekey between tenancies as a straightforward, cost-effective way to reset access without replacing functional hardware.
When Replacement Makes More Sense
After a break-in or attempted break-in, where the lock itself may be damaged. As covered in our guide on what to do after a break-in, a compromised lock often needs full replacement rather than simply rekeying damaged hardware.
When upgrading to a higher security standard. If existing locks predate current British Standard certification or simply offer weaker security than what’s now available, replacement is the only way to genuinely upgrade, since rekeying an older mechanism doesn’t improve its underlying resistance to forced entry.
When a lock has become worn, stiff, or unreliable over time. Mechanical wear affects the lock’s actual function, which rekeying doesn’t address, since it only changes which key operates the mechanism, not the mechanism’s physical condition.
A useful way to think about the distinction is that rekeying addresses who has access, while replacement addresses both access and the underlying quality of the security itself. If your only concern is who might hold a key, rekeying is usually sufficient. If the lock’s condition or standard is also in question, replacement is the more complete answer.
Whether rekeying or full replacement is right for your situation depends on the specific condition and standard of your existing locks. Get in touch for an honest recommendation and a clear quote for whichever genuinely suits your needs.
Frequently asked questions
Generally yes, since rekeying reuses the existing lock hardware and only changes the internal mechanism, avoiding the cost of new hardware that full replacement requires.
If the existing locks are in good condition and meet a reasonable security standard, rekeying is usually sufficient and more cost-effective. If the locks are worn, damaged, or outdated, replacement is the better choice.
Most standard cylinder locks can be rekeyed, provided they're in decent physical condition. A worn or damaged lock isn't a good candidate for rekeying alone, since rekeying doesn't address mechanical wear.
No. Rekeying changes which key operates the existing mechanism, but it doesn't improve the underlying security standard of the hardware itself. Upgrading security standard requires replacement.
Both are typically completed within a relatively short appointment, often under an hour per lock, though the exact time depends on the number of locks involved and any complications with the existing hardware.
Keep reading
Copyright © 2026 123Unlock, Design & Develop by Brand Builders.