Rekeying vs. Lock Replacement: Which Do You Need?
When homeowners want to change their locks, they usually mean one of two things: rekeying (changing the internal pins so old keys don't work) or replacement (removing the old lock and installing a new one). Both achieve the goal of securing your property with new keys, but they differ significantly in cost, time, and when each is appropriate. This guide helps you decide which option is right for your situation.
What Is Lock Rekeying?
Rekeying changes the internal pin configuration of your existing lock cylinder so that old keys no longer operate it. The lock body, deadbolt, handle, and trim stay exactly as they are — only the tiny pins inside the cylinder are changed. A locksmith removes the cylinder, replaces the pins with a new combination, and provides you with new keys that match the updated pins. The entire process takes 5-10 minutes per lock and costs $25-50 per lock cylinder. Your old keys become completely useless, and only your new keys will work.
What Is Lock Replacement?
Lock replacement means removing the entire existing lock assembly — deadbolt, knob, or lever — and installing a brand-new unit. This includes new hardware, a new cylinder with new pins, and new keys. Lock replacement takes 15-60 minutes per lock depending on whether the door is pre-drilled and costs $100-300 per lock including the new hardware.
When to Choose Rekeying
Rekeying is the right choice when:
You just moved into a new home. The existing locks are in good working condition, but you don't know who has copies of the keys. Rekeying gives you new keys without the expense of new hardware. This is the #1 scenario where rekeying makes sense.
You lost a key. If a key is lost or stolen but your locks work fine, rekeying is faster and cheaper than replacing all your locks.
A roommate or tenant moved out. Ensure they can't access the property with their old key.
You want all locks on one key. "Keyed-alike" rekeying adjusts all your locks to work with a single key — no more key ring clutter.
After a relationship change. An ex-partner who had a key should no longer have access. Rekeying is the fastest solution.
When to Choose Lock Replacement
Lock replacement is the right choice when:
Your locks are old, worn, or damaged. Locks that are difficult to turn, loose, corroded, or visibly worn should be replaced rather than rekeyed. Rekeying worn locks extends their life only temporarily.
You want to upgrade security. If your home has builder-grade (ANSI Grade 3) locks, upgrading to Grade 1 or Grade 2 hardware significantly improves security. This requires replacement, not rekeying.
You want to change the lock style. Want to switch from a knob lock to a lever handle, change finishes, or install a smart lock? These require new hardware.
After a break-in. If locks were damaged during a forced entry attempt, they should be replaced — the internal mechanism may be compromised even if the lock appears to still work.
You want different lock features. Upgrading to keyless entry, bump-proof cylinders, or high-security restricted keyways requires new lock hardware.
Cost Comparison
Rekeying Cost
$25-50 per lock cylinder. A typical 4-lock home rekey costs $100-200 total. Includes labor, new pins, and new keys. No new hardware to purchase.
Replacement Cost
$100-300 per lock including hardware. A typical 4-lock home replacement costs $400-1,200 total. Includes new lock hardware, installation labor, and new keys. Grade 1 deadbolts cost more than Grade 3.
Can You Rekey Different Lock Brands to One Key?
Rekeying to one key is only possible when all locks use the same keyway (key shape). Schlage locks use a different keyway than Kwikset locks, so they can't be rekeyed to the same key. If your home has mixed brands, you have three options: rekey each brand to its own key (two keys total), replace all locks with the same brand and rekey to one key, or install Kwikset SmartKey locks which can be rekeyed by the homeowner without a locksmith.
Rekeying vs. Replacement FAQ
Is rekeying as secure as a new lock?
Yes, as long as the lock itself is in good condition. Rekeying creates a completely new key combination — old keys are 100% useless. The security level matches the original lock's grade. The only advantage of replacement is if you're upgrading to a higher-security lock grade.
How long does rekeying take?
5-10 minutes per lock. A full-house rekey (3-5 locks) takes 30-60 minutes. Much faster than lock replacement, which takes 15-60 minutes per lock.
Can I rekey a lock myself?
Kwikset SmartKey locks can be rekeyed by the homeowner using a SmartKey tool. All other locks require a locksmith with professional rekeying tools. DIY rekeying of standard locks is not practical without the proper equipment and training.
Should I rekey or replace after buying a new house?
If the existing locks are in good condition and you like the style, rekeying saves money. If the locks are old, worn, or builder-grade, consider upgrading to Grade 1 hardware during the move-in — you're already investing in your new home's security.
Need help deciding? Call MyKey Locksmith at (214) 888-8755 — our technician will evaluate your locks and recommend the most cost-effective option. Rekeying services | Lock installation