Two Solutions, Very Different Costs
Whether you've just moved into a new home, lost a key, or had a tenant move out, you're faced with a common question: should you rekey your existing locks or replace them entirely? Both options restore your security, but they work differently and suit different situations. Understanding the distinction can save you money without compromising your safety.
What Is Rekeying?
Rekeying means changing the internal pin configuration of an existing lock cylinder so that the old key no longer works and a new key is required. The lock hardware itself — the knob, deadbolt, strike plate, and cylinder housing — stays in place. Only the pins inside the cylinder are changed.
The result: The same lock, brand-new key combination. Anyone with the old key is locked out.
What Is Lock Replacement?
Lock replacement involves removing the entire lock mechanism from the door and installing a new one. This includes the cylinder, housing, latch or bolt, and potentially the strike plate. The old hardware is discarded entirely.
When Rekeying Makes Sense
Rekeying is typically the better choice when:
- You've just moved into a previously owned home or apartment
- You've lost a key or had one stolen
- A tenant, employee, or contractor had key access and no longer should
- Your locks are in good working condition and you're happy with the hardware
- You want all your locks to work on the same key (keyed alike)
Rekeying is almost always significantly cheaper than replacement — a locksmith can rekey most locks for a fraction of the cost of new hardware, and it's just as effective at invalidating old keys.
When Lock Replacement Makes Sense
Replacement is the right call when:
- Your existing lock is old, worn, or not functioning smoothly
- You want to upgrade to a higher security grade (e.g., moving from Grade 3 to Grade 1)
- You want to switch to a smart lock or keypad entry system
- The lock has been damaged during a break-in attempt or forced entry
- The lock brand or model is no longer considered secure by current standards
Side-by-Side Comparison
| Factor | Rekeying | Lock Replacement |
|---|---|---|
| Cost | Lower | Higher |
| Time Required | Quick (15–30 min per lock) | Longer (30–60 min per lock) |
| Hardware Changes | No — same hardware | Yes — entirely new lock |
| Security Upgrade | No upgrade | Possible (choose better grade) |
| Old Keys Work? | No | No |
| Best For | Key control, recent moves | Damage, upgrade, or smart lock |
Can I Do Either Myself?
Lock replacement is relatively DIY-friendly if you're replacing like-for-like hardware on a standard door prep. Rekeying, however, requires a special rekeying kit specific to your lock brand and some technical familiarity with pin tumbler mechanisms. Both tasks are well within the skill set of a licensed locksmith and are usually completed quickly at a reasonable cost.
The Bottom Line
If your locks are functioning well and you simply need to invalidate old keys, rekeying is almost always the smarter financial choice. If your hardware is worn, damaged, or you want a meaningful security upgrade, replacement is worth the extra investment. When in doubt, consult a licensed locksmith — they can assess your specific hardware and recommend the most cost-effective solution.