Rekeying: The Smart Alternative to Changing Your Locks

Most people think “new locks” when they want better security or when they need to stop old keys from working. That instinct costs them two to three times more than they need to spend. In the majority of situations, rekeying is the smarter move — and it’s done in a fraction of the time.

This is the full picture: what rekeying actually is, when it makes sense, when it doesn’t, what it costs in Philadelphia, and the master key option that every landlord in the city should know about.

What Is Rekeying?

Rekeying is the process of changing a lock’s internal pin configuration so that old keys no longer work — without replacing the lock hardware itself.

Here’s how a pin-tumbler lock works: inside the cylinder, a series of spring-loaded pins of varying heights sit in stacks. When the correct key is inserted, it pushes each pin stack to exactly the right height, aligning all the shear lines simultaneously and allowing the cylinder to rotate. The wrong key pushes the pins to the wrong heights — the shear lines don’t align — and the lock doesn’t turn.

Rekeying means removing the cylinder, replacing the key pins (the bottom pins that vary in height) with a different set, and reassembling. The result: the old key no longer pushes the pins to the correct heights. It’s dead. You get new keys cut to match the new pin configuration.

Rekey vs. Replace — The Decision

The right choice comes down to one question: Is the hardware worth keeping?

If your existing lock is an ANSI Grade 1 deadbolt in good condition — smooth action, no visible wear, bolt throws fully — rekeying is the right call. You’re paying to change the secret, not to replace good hardware.

If your existing lock is a builder-grade Grade 3 lock, corroded, worn, stiff to operate, or mechanically compromised, rekeying doesn’t help — you’d be spending $35 to rekey a $20 lock that should be replaced anyway. In that case, replacing with a quality Grade 1 deadbolt and rekeying that new lock to your desired key makes more sense.

When to Rekey

These are the situations where rekeying is clearly the right call:

• Moving into a new home. The previous owners had keys. Real estate agents had keys. Contractors probably had keys. You have no idea how many copies exist. Rekey immediately — before your first night in the house.
• Tenant moved out. Philadelphia landlords: you’re legally and practically required to control access between tenants. Rekeying is the standard. It’s faster than replacing hardware and costs a fraction of the price.
• You lost a key. Assume it’s in someone’s hands, not on the street. Rekey before you regret assuming otherwise.
• A relationship ended. Breakup, divorce, roommate dispute, firing a live-in caregiver. Anyone who had a key and should no longer have access needs to be shut out immediately.
• After a contractor job. You gave a key to a plumber, electrician, or renovator while you were at work. The job is done. Does that person still have a copy? Do their employees? Rekey after any job where someone had unsupervised key access.

When to Replace

Rekeying isn’t always the answer. Here’s when you should replace instead:

• The hardware is worn or damaged. Stiff cylinder, loose bolt, cracked housing. Rekeying a failing lock just means you have a newly rekeyed failing lock.
• You want to upgrade security. Going from a Grade 3 to a Grade 1 lock — or from a standard deadbolt to a high-security Medeco or Mul-T-Lock — requires new hardware. You can’t rekey your way to better security.
• The lock is very old. Pre-1970s locks often use non-standard pin configurations. Replacement pins may not be available, and rekeying may not restore reliable function.
• You want smart lock features. Keypad entry, auto-lock, app control — these require new hardware. A locksmith can install a new smart deadbolt and ensure it’s properly fitted to your door.

Cost Comparison

Here’s the honest price comparison for Philadelphia in 2026:

The math is clear. Rekeying three standard locks costs $75–$135. Replacing those same locks with equivalent hardware costs $240–$525. If the hardware is worth keeping, rekeying saves you 60–80%.

Master Key Systems

If you manage a Philadelphia rental property — or any property with multiple locks — a master key system is worth knowing about.

A master key system is a lock configuration where individual locks each have their own change key (opens only that lock), but all locks also respond to a single master key that opens all of them. Tenants get their change key. You carry the master.

This is standard for Philadelphia landlords who manage multi-unit properties. Instead of carrying a ring with twenty keys, you carry one. When a tenant moves out, you rekey just their unit. Your master key still works because master key systems are designed so that pin changes at the change key level don’t affect the master shear line.

How Long Does Rekeying Take?

A standard pin-tumbler deadbolt takes 15–20 minutes to rekey. A typical Philadelphia rowhouse with three entry points takes 45–60 minutes total, including cutting the new keys and testing all locks.

We come to you at your location — no need to remove locks, bag them up, and bring them anywhere. We bring the pin kits, the key machine, and everything needed to complete the job on-site.

For more on the rekey vs. replacement decision, see our dedicated comparison guide: Rekeying vs. Changing Locks — Which Do You Need?