Rekey vs. Replace Your Locks: What NYC Residents Need to Know

You just moved into a new apartment in Brooklyn. The previous tenant returned their keys — or said they did. The landlord had it re-keyed, maybe. Should you trust that? Or are you in a building where five different sets of keys have floated around over the past decade?

Whether you're a new tenant, a homeowner who's had a break-in attempt, or just someone who lost a key, the question is the same: should you rekey or replace your locks? Here's the honest answer.

What Is Rekeying?

Rekeying is the process of changing the internal pin configuration of your existing lock cylinder so that the old key no longer works. A locksmith removes the cylinder, replaces the tumbler pins with a different set, and hands you a new key that fits the new configuration.

The lock body, deadbolt, and hardware all stay the same. Only the internal mechanism changes — and with it, every old key becomes useless.

Rekeying takes about 10–20 minutes per lock and typically costs $30–$60 per cylinder when done by a professional.

What Is Lock Replacement?

Lock replacement means removing the entire lock assembly — hardware, cylinder, strike plate, and all — and installing a new unit. You're starting fresh with new hardware, a new mechanism, and new keys.

Replacement takes longer and costs more, but it's sometimes the right call.

When to Rekey

Rekeying is the right choice when:

• You just moved in. A new tenant or homeowner should always rekey immediately. You have no idea who has copies of the existing key — the previous tenant, their ex, a contractor, the building handyman.
• You lost a key. As long as your lock is in good physical condition, rekeying is the most cost-effective way to secure yourself after a lost or stolen key.
• You had a roommate or employee move out. Anyone who had a key no longer needs access. Rekeying is faster than changing every lock.
• Your locks are relatively new and in good shape. If the hardware is solid and the deadbolt functions correctly, there's no reason to replace it just to revoke access.
• You want all locks keyed alike. A locksmith can rekey multiple locks so one key works on all of them — front door, back door, garage — without replacing any hardware.

When to Replace

Lock replacement makes more sense when:

• Your locks are old, worn, or low-grade. Many NYC apartments still have builder-grade locks that offer minimal protection. If your deadbolt is a $30 big-box store unit, upgrading to a high-security lock is worth the investment.
• There's been a break-in attempt. Forced entry can damage the lock housing, door frame, or cylinder in ways that aren't always visible. Damaged hardware should be replaced, not just rekeyed.
• The lock is malfunctioning. Stiff action, difficulty turning the key, or a cylinder that spins without engaging the bolt are signs of wear or damage. Rekeying a failing lock just gives you a new key to a lock that's about to fail.
• You want to upgrade security. This is the best reason to replace rather than rekey. Swapping a standard deadbolt for a Mul-T-Lock or Medeco high-security cylinder gives you pick-resistance, drill-resistance, and restricted key control — the old key literally cannot be copied at a hardware store without authorization.
• You want smart lock functionality. If you want keypad entry, phone control, or guest access codes, you'll need new hardware regardless of rekeying.

The Security Upgrade Argument

Here's something worth knowing: most NYC apartment doors are not as secure as people assume. Standard Grade 3 deadbolts — the kind installed as default in most residential buildings — can be picked, bumped, or shimmed by anyone with basic tools and a YouTube education.

Mul-T-Lock and Medeco locks — both of which we carry and install — operate on patented cylinder technology that makes picking and bumping dramatically harder. They also come with key control: copies can only be made by an authorized dealer (like us) with the proper documentation. That means if a key walks out the door, it can't be duplicated at the corner hardware store.

If you're going to replace, replace with something that actually raises your security level.

Can I Rekey My Own Locks?

Technically, yes — rekey kits are available at hardware stores for some lock brands. In practice, it requires the right tools, the right replacement pins for your specific cylinder, and some experience. Get it wrong and you can lock yourself out permanently or damage the cylinder. For the price difference, it's almost always worth having a professional do it cleanly in 15 minutes.

What ASK Locksmith Recommends for NYC Apartments

If you're a new tenant in a rental:

1. Rekey the existing deadbolt immediately (assuming it's in good condition)
2. Make 2–3 spare keys
3. Consider upgrading if the existing lock is low-grade

If you're a homeowner or condo owner:

1. Consider upgrading to a high-security cylinder on the primary entry door
2. Have all locks keyed alike for convenience
3. Add a smart lock if you want remote access or guest codes

Quick Comparison: Rekey vs. Replace

The bottom line: rekey when you trust the hardware and just need to revoke old access. Replace when the hardware itself is the problem — or when you want to meaningfully improve your security. Either way, ASK Locksmith can handle it quickly and affordably.