Lock Rekey Toronto: Rekeying & Master Key Systems for Homes and Businesses (2026)

Most door locks in Toronto homes and businesses are pin tumbler locks. Inside the cylinder there is a row of small pins cut to different lengths. When the right key goes in, the pins line up at exactly the right height and the cylinder turns. When any other key goes in, they don't, and the lock stays shut.

Rekeying means taking the cylinder apart and replacing those pins with a new set cut to match a new key. The lock body, the handle, the deadbolt and the strike in the frame all stay in place. Only the combination changes. From the moment the cylinder goes back in, every old key in circulation is useless.

That is why rekeying is usually the first thing we suggest after keys go missing, after a tenant or employee leaves, or when you buy a home and have no idea how many copies of the keys are out there. The locks are fine. The problem is who can open them.

If the lock itself is worn, damaged or low quality, rekeying doesn't fix that. In those cases a full lock change or a commercial lock replacement makes more sense, and we'll tell you so when we see the hardware.

On commercial doors, a stiff or sticky key is often not the cylinder at all. It can be a door that has dropped so the latch drags on the strike, or a door closer pulling the door tight against the frame. We check the door as well as the lock, because a new key in a misaligned door still won't turn nicely.

A master key system lets different keys open different combinations of doors. The owner or property manager carries one key that opens everything. A manager's key might open the front door, the office and the stockroom. A staff key might only open the front door. Each lock is pinned so that it accepts its own change key and the master key above it.

How the levels usually work

Grand master: opens every lock in the system, usually held by the owner or building manager.

Master: opens a group of doors, such as one floor, one unit or one department.

Change key: opens a single door or a small set of doors, given to staff or tenants.

Who uses master key systems

Retail stores with front, back and office doors. Restaurants that need kitchen staff to get in but not into the office. Small office buildings, clinics, daycares, places of worship, warehouses, and residential buildings where the superintendent needs access to common areas and service rooms.

Keep the system under control

A master key system is only as good as its key control. We recommend a simple key register listing who holds which key, keys stamped "Do Not Duplicate", and, where the risk is higher, a restricted keyway so that copies can't be cut at a hardware store. When a key goes missing, only the locks on that part of the system need to be rekeyed, not the whole building.

In rental properties, rekeying between tenants is the simplest way to keep the next tenant safe from anyone holding an old key. In Ontario, the Residential Tenancies Act does not allow a landlord to change or alter the locking system of a rental unit during a tenancy without giving the tenant replacement keys, and tenants can't change locks without the landlord's consent. Rekeying between tenancies, when the unit is empty, avoids both issues.

For condos and apartment buildings, we rekey suite doors, service rooms, garbage rooms and mailrooms, and set up master key systems so the superintendent can reach every common area on one key. Many suite entry doors in Toronto buildings are fire-rated, so any hardware change needs to keep the door self-closing and latching. See condo door replacement rules and fire-rated door requirements.

Buildings with fob or keypad entry still have mechanical cylinders somewhere: as override locks on the main door, on service rooms and on stairwell doors. Those need rekeying too when keys go missing. If the access control side of the door is the problem, we handle electric strikes and mag locks as well.

Residential locks

Deadbolts, knob and lever sets, handle sets on front doors, side and back door locks, garage entry doors and patio door cylinders. Many homes end up with a mix of brands over the years. Where the keyways don't match, we can often switch cylinders so one key works everywhere. Multi-point locks on European-style and patio doors usually have a replaceable cylinder that can be rekeyed or swapped.

Commercial locks

Mortise locks on office and entrance doors, rim cylinders on panic bars and exit devices, storefront deadlocks on aluminum doors, interchangeable-core cylinders, and padlocks used on gates and roll-up doors. Commercial cylinders are usually built to a higher grade, and the keying plan matters more because more people carry keys. See door hardware grades (ANSI/BHMA).

High-security and restricted keys

If you want keys that can't be copied without authorization, a restricted or patented keyway is the upgrade. The cylinder is replaced rather than rekeyed, and duplicate keys are controlled. This is common for businesses that have had problems with unauthorized copies.

For general pricing on commercial work, see our commercial door repair cost guide. For homes, see the residential door repair cost guide.

Before you call, these guides may help: front door security upgrades, door hardware grades, smart locks on existing doors, condo door rules, commercial door maintenance contracts and common door problems in the GTA. Other services: panic bar installation, electric strike repair, steel door repair, residential door repair and emergency door repair.