How a Master Key System Works (And When Denver Businesses Need One)

If you manage a Denver office, retail location, restaurant, or multi-unit property, you've probably wrestled with this: the manager needs every door, the night shift needs three, the cleaner needs two, and the owner needs all of them. Handing out separate keys creates a big key ring and a lot of security drift.

A master key system is one common approach.

The basics

Every door still has its own unique change key. Each cylinder is also pinned so that one or more master keys open it.

• Change key (CK): opens one door.
• Master key (MK): opens a group of doors.
• Grand master (GMK): opens every door in the building.

The trade-off

Master-keyed cylinders have extra pins, which can make them slightly easier to pick than a standard cylinder. For most businesses this is a non-issue in practice, but if you store cash, controlled substances, or sensitive data, ask about restricted or patented keyways.

Keeping the system secure over time

1. Keep a key control log: who has which key, when they got it, and when they returned it.
2. Rekey on turnover, not "eventually."
3. Walk every door and reconcile the log periodically.

When to think about electronic access instead

If you have many doors, frequent turnover, or compliance requirements, an electronic access control system can be worth the investment because disabling a fob is faster than rekeying cylinders. Sometimes a hybrid makes sense — electronic exteriors and mechanical interiors. Learn more on our commercial locksmith page or get in touch.