Gate & Building Entry Locks: before you call

A neighbour mentions, in passing, that the key from three tenants ago still lets him into the building's front door. Nobody changed it after he moved out, and now the property manager wants to know exactly how many keys are still floating around out there.

Worth answering before the call

Is the gate sagging, dragging, or hard to close by hand? Are there other gates on the property that should share a key? Has the lock been stiff or slow in cold weather?

What is a good option for a gate that delivery drivers or a maintenance crew need occasional access to?

A keypad or a lockbox with a rotating code works well there, since access can be shared without handing out a physical key that has to come back later. A weather-rated cylinder with a separate access key is another option if the property already runs on a keyed system. The locksmith can talk through how often the code should change and who on site should know it, so the gate stays convenient without staying open to everyone.

How can I tell if the problem is the lock or just the gate's alignment?

A simple check is to lift or support the gate slightly while someone else turns the key: if the bolt suddenly moves freely, the gate's weight was pulling it out of line with the strike, not the lock itself. A key that turns smoothly but never releases the bolt, regardless of how the gate is held, points more toward the cylinder or its connection to the latch. Either way, the locksmith checks both possibilities directly rather than assuming which one it is.