A lock change sounds like one job with one price, but it is really two different jobs that happen to end with the same result: your old keys stop working. One of them keeps the lock you already own and changes what key it answers to. The other takes the lock off the door and puts a new one on. Most people in Toronto call asking for the second and actually need the first.

The difference matters because it decides how long the visit takes, what the hardware looks like afterwards, and whether you end up with one key for the whole house or four keys on a ring you can never sort out. Here is how the two options differ, and the situations where one is clearly the better call.

What rekeying actually changes

Inside most residential cylinders sits a stack of small spring-loaded pins. The cut pattern on your key pushes each pin to exactly the height that lets the cylinder turn. Rekeying means swapping those pins for a different combination of heights and cutting a new key to match. The lock body, the handle, the deadbolt, the strike plate and the holes in your door all stay exactly where they are.

Why that is usually enough

If your concern is who has a key — a tenant moved out, a contractor kept one, a set went missing on the TTC — rekeying solves the whole problem. Nothing about the old keys survives the change. The lock does not care that it was once keyed differently, and a cylinder that turns smoothly today will turn smoothly on a new pin stack.

It is also the quiet option. No new boreholes, no mismatched finish where an old rosette sat, no discovering that the replacement lockset needs a backset your 1950s door does not have. For a door that is otherwise sound, rekeying is the least invasive thing you can do to it.

When replacing is the honest answer

Rekeying assumes the lock is mechanically healthy. Plenty are not, and a technician who rekeys a worn cylinder has just given you a brand new key that works badly.

Wear you can feel in the key

Signs that the cylinder itself is finished: you have to lift, jiggle or pull the door toward you before the key will turn; the key goes in but needs a wiggle to find the turning point; the thumbturn has play in it before anything engages. Those point to rounded pin chambers, a worn plug or a tired tailpiece, and no new pin stack fixes any of them.

Hardware that no longer matches the door

Sometimes the lock works fine and still has to go. A knob where you now want a lever. A single-cylinder deadbolt on a door with glass beside it. A builder-grade lockset on a front entry that takes the brunt of a Toronto winter. In those cases you are not buying security, you are buying hardware that suits how the door gets used, and a straightforward lock change in Toronto is the simpler path.

Damage from a forced entry

After a break-in attempt, replacement is almost always the call — and not only for the lock. Prying bends the bolt, spreads the jamb and tears out the strike screws. A new cylinder in a jamb that no longer holds the bolt is decoration. This is where a lock conversation turns into a residential door repair conversation.

Keyed alike: the reason most people call

The most common request is not really about security at all. It is about carrying one key instead of three. Front door, side door, garage man door and basement entry can usually be rekeyed to a single key, provided all the cylinders are the same keyway. That is the catch: a Weiser-keyway deadbolt and a Schlage-keyway knob cannot share a key, no matter how they are pinned. When keyways do not match, one of the locks gets replaced so the set can be unified.

It is worth deciding this before the work starts. Unifying four doors is one visit; doing it door by door over a year means paying for the visits and still ending up with two keys.

What the decision costs you in time, not just money

Rekeying is measured in minutes per cylinder once the technician is at the door. Replacement adds variables: whether the new lockset matches the existing boreholes and backset, whether the strike plate pocket needs chiselling, whether the old finish left a mark. On an older Toronto door with a non-standard prep, that is the difference between a short visit and an afternoon.

Ask for the decision to be made at the door, not over the phone. A technician who looks at the cylinder, turns the key a few times and checks how the bolt enters the strike can tell you in a minute which job you are buying. Anyone quoting replacement sight unseen is quoting the more expensive option by default.

Where rekeying is not enough

• You do not know how many keys exist. Rekeying handles this fine — but only if every cylinder on the property is done at once. Missing one side door defeats the exercise.
• Master keying is involved. Shared buildings, offices and multi-tenant setups usually need a planned key system rather than a one-off change, which is closer to a planned commercial lock replacement scope than a residential one.
• The lock is part of a multi-point system. On an entry door with hooks and rollers driven by one gearbox, the cylinder is only the trigger. If the gearbox is the problem, rekeying changes nothing you care about.
• Restricted or patented keys. Some cylinders only accept keys from a controlled blank. That is a feature, not a fault, but it changes who can cut the new key.

Frequently asked questions

Does rekeying make a lock less secure than a new one?

No. A correctly rekeyed cylinder is exactly as strong as it was the day before. Security comes from the grade of the lock, the length of the bolt and the strength of the strike and jamb — not from the age of the pin stack.

Can every lock be rekeyed?

Most standard residential cylinders can. Some sealed, cheap or heavily worn units cannot be taken apart usefully, and a few high-security systems require the manufacturer’s own process. A technician can tell by the keyway and the brand stamp.

I lost the only key. Can the lock still be rekeyed?

Usually yes. The cylinder can be picked or removed and then rekeyed to a new key. It takes longer than rekeying with a working key in hand, and on some cylinders removal is the faster route.

How often should locks be changed?

There is no calendar for it. The trigger is an event, not a date: a move, a tenant change, a lost key, a break-in attempt, or hardware that has started to feel wrong in the hand.

The short version

If the lock works and the only problem is who holds a key, rekey it. If the key feels wrong in the cylinder, the hardware no longer suits the door, or something has been pried, replace it. And if you are chasing one key for the whole house, sort the keyways out first — that is the decision that actually determines the job.