A master key system lets different staff open different combinations of doors with individual keys, while a single master key opens everything. Here is how they work, what they cost, and when your business needs one.
What Is a Master Key System?
A master key system is a lock arrangement where different keys open different combinations of doors, while a single master key opens all of them. It is the standard security infrastructure for offices, commercial buildings, hotels, schools and multi-unit residential properties.
At its simplest: individual keys each open one specific door; the master key opens every door. Larger systems add more levels — a department manager holds a key that opens their area plus common spaces; a director holds a key that opens the whole building.
Why Standard Locks Fail for Businesses
Domestic-grade locks were not designed for commercial key management. In most small businesses without a managed system, the key history looks like this: a set of keys was cut when the business moved in. More copies were made as staff joined. Some were returned when staff left; many were not. After a few years, an unknown number of people hold working keys to your premises.
Restricted-profile cylinders — where the key profile is patented and duplication requires an authorisation card held by the business owner — are the solution to this problem. Once fitted, keys can only be cut with the card present.
What a Master Key System Involves
Setting up a system requires:
1. **Site survey:** Mapping all access points and defining who needs access to which doors
2. **Level design:** Deciding how many key tiers the system needs (individual, supervisor, management, master)
3. **Cylinder installation:** High-security cylinders keyed to the system throughout
4. **Key documentation:** A formal record of who holds each key
Costs
A small office with 5 doors: approximately £400–£800 for cylinders and setup. Larger premises with 20+ access points: proportionally more. Restricted key cutting typically costs £20–£40 per additional key.
When to Consider One
Call 07984 547185 to discuss your commercial security requirements. We serve businesses across South London and SE postcodes.