Master Keying

What is a Master Key System?

A master key system is a structured way to control access across multiple doors using a hierarchy of keys. It allows different levels of access with different keys—all while maintaining high security and organization. These systems are ideal for commercial buildings, schools, multi-tenant properties, industrial facilities, and anywhere layered access is needed.

Master Key Terminology:

Change Key (CK): Opens only one specific lock.
Master Key (MK): Opens all locks in a designated group or system.
Grand Master Key (GMK): Opens multiple master key groups within a larger system.
Keyed Alike (KA): All locks operate with the same key—good for small or single-access zones.
Keyed Differently (KD): Each lock has a unique key—unless part of a master system.
Pinning Chart: The codebook used to design and map which pins go in which cylinders

Common Use Cases:

Office buildings: Individual keys for employees, with managers holding master keys.
Apartments & condos: Tenants have private keys; property managers have full access.
Warehouses & industrial sites: Controlled access for contractors, janitorial staff, or vendors.
Schools & campuses: Tiered access for teachers, staff, and administrators.

When To Call Keys Plus

You’re issuing too many keys and it’s hard to keep track of who has what.
You need to rekey part of a building without affecting access elsewhere.
You’re expanding your building or workforce and need an access plan that scales.
You’ve had a security breach or lost keys and need to reconfigure quickly.
You want a custom solution with key control and restricted keyways (to prevent unauthorized duplication).

Contact Us!

Need to give different people access to different doors—without carrying a dozen keys? A custom master key system from Keys Plus gives you security and convenience in one solution. From office suites to apartment complexes, we build systems that work for you.