How Lock Rekeying Works: A Step-by-Step Guide From a Perth Locksmith
- •Rekeying changes the internal pin configuration — your old keys stop working instantly.
- •A professional rekey takes around 20–30 minutes per lock and costs less than full replacement.
- •You do not need to replace the lock hardware — only the internal pins are changed.
- •Rekeying is the smart move after moving home, losing keys, or a tenancy change.
- •A licensed locksmith ensures the rekey is done correctly so the lock performs reliably.
You’ve just moved into a new Perth home, lost a set of keys, or changed tenants — and now you’re wondering whether to rekey or replace your locks entirely. Rekeying is almost always faster, cheaper, and just as effective — but most homeowners have no idea what actually happens inside the lock. This guide walks you through the process step by step, so you know exactly what to expect.
What Is Lock Rekeying and How Does It Actually Work?
Understanding the mechanics that make old keys useless in minutes.
Inside every pin tumbler lock — the most common residential lock type in Perth — there are a series of spring-loaded pin stacks. Each stack has a key pin and a driver pin. When the correct key is inserted, the pin stacks align perfectly at the shear line, allowing the cylinder to rotate and the lock to open.
Rekeying replaces the key pins with a new set of pins in different heights. The result: the old key no longer aligns the pins at the shear line, so it can’t turn the cylinder. A new key — cut to match the new pin heights — becomes the only one that works. The lock body, door hardware, and strike plate all stay exactly as they are.
Rekeying doesn’t weaken your lock. The security rating of the lock remains unchanged — only the key that operates it changes. If your lock is in good condition, a rekey delivers the same outcome as buying a brand-new lock at a fraction of the cost.
What Tools Does a Locksmith Use to Rekey a Lock?
Professional rekeying requires specific tools — this is not a DIY job.
A licensed locksmith arrives with a rekeying kit specific to your lock brand. These kits contain a plug follower tool, a key decoder, a variety of replacement pin sizes, and a pinning tray to keep the small components organised. Different lock brands — Lockwood, Schlage, Assa Abloy — use different pin sizes and require brand-matched kits.
Attempting a rekey without the correct tools risks losing pins inside the cylinder or damaging the plug — which can leave you with a lock that doesn’t function at all. This is one of the clearest reasons why professional rekeying is worth the call, as covered in detail in our full range of locksmith services.
Step-by-Step: How a Perth Locksmith Rekeys Your Lock
From removing the cylinder to handing over your new keys — here's the full process.
Step 1: Remove the lock cylinder. The locksmith removes the lock from the door using the existing key to turn the plug to the open position. A plug follower tool is inserted to hold the driver pins and springs in place while the plug slides out cleanly.
Step 2: Remove the existing key pins. With the plug out, the locksmith uses the pinning tray to catch and remove the existing key pins one by one. The driver pins and springs remain untouched in the lock housing — they don’t change during a rekey.
Step 3: Decode the new key and select replacement pins. The locksmith uses a key decoder or directly reads the new key’s cut depths to determine which replacement pin heights are needed for each chamber. Pins are selected from the kit and loaded into the plug in the correct order.
Step 4: Reassemble and test. The plug is reinserted into the cylinder housing, the lock is refitted to the door, and the locksmith tests the new key multiple times — including under load — to confirm smooth, reliable operation. The old key is tested too, to confirm it no longer operates the lock.
Always ask your locksmith to test the old key in front of you before they leave. This gives you immediate confirmation that previous keyholders — former owners, contractors, or ex-tenants — no longer have access to your property.
When Should You Rekey Instead of Replacing the Lock Entirely?
Rekeying is the right call in most situations — but not every situation.
Rekeying makes sense when your lock is mechanically sound and in good condition. The most common triggers are moving into a new home (previous owners or real estate agents may hold key copies), a tenancy change, or lost and stolen keys — where the urgency is immediate. If you’ve lost keys in Perth, an immediate rekey is the fastest way to eliminate the risk of an opportunistic break-in.
Full lock replacement is the better choice when the hardware is damaged, corroded, or a low-security grade that no longer meets current standards. Our complete guide to lock installation for Perth homes and businesses walks through the decision criteria in detail — including the specific warning signs that mean rekeying alone won’t be enough. The broader context sits in The Complete Guide to Lock Rekeying in Perth, which covers costs, timing, and the full range of scenarios where rekeying applies.
- •Rekey: moving into a new home — unknown key copies may exist with previous owners or contractors
- •Rekey: lost or stolen keys — eliminate access risk immediately without buying new hardware
- •Rekey: tenancy changeover — confirm only current occupants hold working keys
- •Replace: visible rust, corrosion, or physical damage to the lock body
- •Replace: upgrading from a basic knob lock to a deadbolt on an exterior door
Your Lock Rekeying Questions Answered
Straight answers to what Perth homeowners ask most before booking a rekey.
How Long Does a Lock Rekey Take?
For a standard residential deadbolt, a professional rekey typically takes around 20–30 minutes per lock. If you have multiple locks to rekey in one visit — which is common after moving into a new home — a locksmith can often work through several locks consecutively, making the whole job efficient and cost-effective.
Can All Locks Be Rekeyed?
Most standard pin tumbler locks — including the majority of residential deadbolts fitted to Perth homes — can be rekeyed. Some high-security restricted keyway locks require specialist rekeying equipment. Very old or heavily corroded locks may not rekey cleanly; in those cases, full replacement is the safer outcome. A licensed locksmith can assess your specific hardware on the spot.
Do I Need to Be Home for a Lock Rekey?
Yes — a locksmith needs access to the door from both sides to remove and refit the cylinder correctly. You’ll also want to be present to receive your new keys, test the lock yourself, and confirm the old key no longer works. It’s a short appointment that’s worth being home for.
Is Rekeying as Secure as Buying a Brand-New Lock?
Yes — provided the lock body is in good condition. Rekeying changes the only thing that matters for key control: which key operates the lock. The security rating, pick resistance, and forced-entry resistance of the lock all remain identical. If the lock itself is worn or low-grade, that’s a separate issue that a rekey won’t fix — but it doesn’t diminish rekeying as a security measure on a sound lock.
Ready to Rekey Your Perth Property?
Whether you’ve just moved in, lost a key, or simply want peace of mind, Ultimate Lock is available 24/7 across Perth — call 0481 365 802 now or send us a message to book a rekey at a time that suits you.
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Part of our guide: The Complete Guide to Lock Rekeying in Perth: What It Is, When You Need It & What It Costs