That's a really practical and common problem in many cities. In a high-theft area, the goal isn't just to keep the lid closed against animals, but to deter people from easily accessing or even stealing the entire bin. The most secure mechanism combines physical robustness with a reliable locking system.
For maximum security, you want a bin with a heavy-duty, integrated locking bar or latch. Look for bins made of thick, durable plastic or galvanized steel where the lid is attached with robust, non-removable hinges. The best mechanism is a steel hasp and staple on the lid and the bin body, allowing you to use a padlock. This is a proven, physical deterrent. Avoid simple flip lids or push-button latches that can be easily pried open.
Some modern options include internal locking mechanisms that require a key or a specialized tool to open from the outside, but these can be cumbersome for daily use. A good compromise is a bin with a tamper-resistant, one-way opening system—where you need a foot pedal or a handle to open it, but it automatically locks when closed. This prevents casual rummaging.
Ultimately, the most secure setup is a sturdy, anchored bin (if possible) with a visible padlock on a strong hasp. It signals that the contents are not easily accessible, which is often enough to make thieves move on to an easier target. Pair this with a community strategy of putting bins out only on collection morning, if feasible, to reduce their exposure time.