Master key system

Definition

A keying hierarchy giving one key access to many locks, administered for a fee.

Why It Matters

A master key system is administered trust: records of who holds what, a keying chart the building depends on, and scheduled rekeying when people leave. The administration recurs and billing follows it, which is why institutional key accounts are the durable end of the trade. Verify the records exist in writing and transfer with the business, because a system that lives in the seller's memory is a liability wearing a revenue line's clothes.