That's a great question, and a common challenge in many cities. The best lock for securing an urban trash bin to a fixed pole is one that balances high security with practicality for daily use. Based on common experience and security recommendations, a heavy-duty bike lock, specifically a hardened steel chain lock or a robust U-lock (D-lock), tends to work best.
Here’s why: These locks are specifically designed to resist bolt cutters, saws, and casual vandalism—the main threats to a bin. A thick, hardened steel chain (at least 12mm thick) allows flexibility to loop through the bin's handle and around a pole, then secured with a quality padlock. A short, shackled U-lock is also excellent if the bin handle and pole alignment allows it, offering even greater resistance to cutting tools.
Avoid cheap cable or combination locks, as they are easily snipped. The goal is to be a more difficult target than the next bin. For permanent solutions, specialty bin locks that bolt onto the bin itself exist, but a high-quality bike lock is often the most accessible and effective off-the-shelf option. Remember to loop the lock through both the bin's secure handle and the pole, keeping the locking mechanism tucked away to deter tampering. This simple step significantly reduces theft, wind-blown mess, and unauthorized use.