When a Master Key Goes Missing: Lessons From a Costly Rekeying in Ontario

In the quiet west end of Guelph, Ontario, a seemingly simple security breach turned into a major expense for a residential property — and a cautionary tale for property owners, managers, and residents everywhere. In April 2025, a master key for a multi-unit apartment building was stolen and never recovered. Because that single key could open every lock in the building, the owners had no choice but to replace every lock across the property — an operation expected to cost at least $12,000.

Read the full report here: Big bill to replace locks after master key stolen at west end apartment building

Why This Incident Matters

A master key system is designed for convenience — one key that opens multiple doors, whether individual units, common spaces, or service areas. But that convenience comes with a significant risk: if the master key is lost or stolen, every lock it can open must be assumed compromised. In this case, the loss of a single key triggered a building-wide security overhaul.

This kind of incident rarely makes national headlines, but its implications are profound for anyone responsible for property access and security:

• Security Risk: A lost master key creates an immediate security breach that cannot be ignored.

• Financial Impact: Rekeying a whole building is expensive — far more than simply replacing one lock or key.

• Operational Disruption: Replacing locks affects residents, maintenance schedules, and tenant relations.

The Hidden Costs of Traditional Keys

This story illustrates a broader problem with conventional mechanical key systems: physical keys are easy to lose and hard to track. Property managers and building owners must plan for the day something doesn’t go right — and when that day arrives in the form of a lost master key, the costs go far beyond the purchase of new hardware.

In apartment buildings, condos, and other multi-tenant properties:

• Master keys are often held by multiple staff or vendors.

• Physical keys can be duplicated or mishandled without clear accountability.

• Once out of custody, there’s no reliable way to know who has access.

That means, when something goes missing, the only secure solution is often to start over with new locks — a costly and disruptive undertaking.

A Broader Lesson About Access Control

Incidents like this don’t make the daily news cycle unless they involve dramatic crime or legal action. But for property owners and managers, they do matter.

This event highlights why so many modern housing communities are transitioning away from traditional lock and key systems toward digital and keyless access controls:

• No physical keys to misplace

• Centralized control over who has access

• Ability to deactivate access instantly if a credential is lost

• Audit trails that track who accessed what and when

These capabilities help minimize risk, reduce operational disruption, and protect both residents and assets.

Takeaway

The $12,000 rekey bill in Ontario may sound like an outlier — but it’s a real cost with real consequences for a real building and real residents. It’s a cautionary example of what can happen when a single point of access control is compromised.

For property managers, housing authorities, and facilities teams, this incident reinforces a key truth:

When access control fails, the consequences go well beyond inconvenience.

And that’s exactly why modern keyless access solutions, paired with professional integration and oversight, are becoming the standard — reducing risk, simplifying operations, and keeping residents safe.

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About Locks In the News
Locks In the News is GoKeyless’ ongoing commentary on real-world access control failures and challenges reported in the news — from homeowners locked out after losing keys to building-wide access issues in apartments, student housing, and commercial properties. We break down what happened, why it matters, and what property owners, homeowners, and managers can do differently, drawing on our experience designing and supporting reliable keyless access solutions for commercial, residential and multi-family environments.

Fair-Use Notice
This article references publicly available news reporting for the purpose of commentary, analysis, and education. GoKeyless is not affiliated with, endorsed by, or representing the organizations or properties mentioned. All trademarks and property names remain the property of their respective owners.