Rekeying a door lock is one of the most practical and cost-effective security measures available to homeowners and businesses. Yet many people are unsure exactly when it is necessary — and end up either ignoring situations that warrant it or spending more on full lock replacement when rekeying would have been sufficient. Understanding the right circumstances for rekeying helps you make smarter decisions about your property's security.

What Does Rekeying Actually Do?

Rekeying changes the internal pin configuration of a lock cylinder so that the existing key no longer works and a new key is required to operate it. The lock body, hardware, and installation remain completely intact — only the pins inside the cylinder are replaced. The result is the same level of security as before, with full key control restored. It is faster and less expensive than replacing the lock entirely, and in most cases it is just as effective.

When You Move Into a New Home

Moving into a new property — whether purchased or rented — is one of the clearest situations where rekeying is warranted. You have no way of knowing how many copies of the existing keys are in circulation, who holds them, or whether previous occupants, contractors, or real estate agents have retained copies. Rekeying all entry locks immediately after taking possession gives you complete key control from day one, at a fraction of the cost of replacing every lock.

After a Change of Tenants or Roommates

For landlords and property managers, rekeying between tenancies is a standard security practice. Even when a departing tenant returns their keys, there is no guarantee that copies were not made during the tenancy. Rekeying protects the incoming tenant and limits the landlord's liability. The same logic applies when a roommate moves out of a shared property — rekeying ensures that only current residents have access.

After a Lost or Stolen Key

A lost key is a security vulnerability that is easy to underestimate. If you cannot confirm that the key was simply misplaced somewhere inside your home, you should assume it could be in someone else's hands. A stolen key — particularly one lost alongside identification that reveals your address — is a more urgent situation. Rekeying the affected locks promptly eliminates the risk posed by the missing key without requiring any new hardware.

After a Relationship Breakdown or Staff Departure

When a relationship ends and a former partner had a key to your home, rekeying is a straightforward way to restore your sense of security and privacy. For businesses, rekeying after the departure of an employee who held a key — particularly one who left under difficult circumstances — is a basic access control measure. The cost is minimal relative to the peace of mind it provides.

After a Break-In or Attempted Break-In

If your property has been broken into or shows signs of an attempted entry, a security assessment is essential before rekeying or replacing locks. In some cases, the lock itself may have been damaged or compromised during the incident and will need to be replaced rather than rekeyed. A professional locksmith can assess the condition of the hardware and advise on the most appropriate response, which may include upgrading to a higher-security lock as part of the remediation.

When You Have Lost Track of Key Copies

Over time, keys get distributed to family members, neighbours, dog walkers, housekeepers, and contractors. If you have lost track of how many copies exist or who currently holds them, rekeying resets your key control entirely. Starting fresh with a known, limited set of keys is far more practical than trying to account for every copy that may have been made over the years.

When Rekeying Is Not Enough

Rekeying is the right solution when the lock hardware itself is in good condition and the security grade is appropriate for your needs. If the lock is worn, damaged, or a low-grade product that offers insufficient resistance to forced entry, replacement is the better investment. A professional locksmith can assess your existing hardware honestly and recommend rekeying or replacement based on the actual condition and security level of your locks — not on what generates the higher bill.

Locksmith Care — Rekeying and Lock Services Across the GTA

Locksmith Care provides fast, professional rekeying and lock repair services across Toronto and the Greater Toronto Area. Our licensed and insured technicians carry rekeying equipment on every service vehicle and can complete most residential rekeys in a single visit. Available 12 hours a day, 7 days a week. Call us at 416-828-2596 for a free quote or to book a same-day appointment.