The question comes up constantly, usually right after a move, a breakup, or the vague unease of realizing you don't actually know how many keys exist to your front door. The honest answer is: it depends on what's wrong with the lock, not just who has a key to it.

When rekeying is enough

Rekeying replaces the pins inside your existing cylinder so that old keys stop working, while the hardware itself — the deadbolt, the lever, the finish you picked out — stays exactly the same. It's the right call when:

  • The lock itself works fine, you just don't trust who has a copy of the key
  • You've moved into a new place and want a clean slate without replacing hardware you already like
  • A key was lost, but the lock isn't damaged

It's also the cheaper option, usually by a wide margin, and it takes a locksmith about as long as changing a light fixture — most rekeys are done in under 20 minutes per lock.

When you actually need a new lock

Replacement makes sense when the lock itself is the problem, not just who might have a key to it:

  • The lock is worn, sticking, or the bolt doesn't throw fully into the strike anymore
  • You're upgrading from a builder-grade knob to a Grade 1 or 2 deadbolt for real security
  • You want keyless entry — a keypad or smart lock — which requires new hardware, not new pins
  • The lock was forced or damaged during a break-in attempt

A middle option: rekey now, upgrade later

If you've just moved and the existing hardware is decent but not great, rekeying immediately and budgeting for a deadbolt upgrade down the line is a completely reasonable way to split the cost over time. Security-wise, a rekeyed lock with pins only you control is far better than a brand-new lock that a previous tenant's contractor, dog walker, or ex still has a key to.

What it actually costs

Rekeying is priced per lock, and most homes need two or three done (front door, back door, sometimes a garage entry). New hardware adds the cost of the lock itself on top of labour. A locksmith worth calling will quote both options on the same visit so you're not guessing.