A single master key may work in small facilities, but once you have more than fifty lockers and more than three shift staff, the risks multiply quickly. If a key is lost or leaked, the facility must rekey each lock individually, and the cost and downtime become hard to predict. More importantly, a master key cannot answer the most basic audit question: 'who opened which locker, and when.' The first decision point in procurement is acknowledging that a single key cannot carry management responsibility.

Mechanical master key systems offer low installation costs and require no power or network, making them suitable for facilities with dispersed lockers and no IT staff. However, permission changes require rekeying, and a lost key is a physical cost. IoT smart locks with a cloud platform are the opposite—permissions can be revoked remotely and opening records are automatically stored, but they require stable power and network infrastructure. When purchasing, calculate the total cost of ownership per locker rather than just the lock unit price, and confirm specifications with the supplier, including the number of permission levels, maximum card issuance, and offline backup mechanisms.