That's a great and very practical question! The answer really depends on the specific type of bin and where you're sourcing it from. Generally, most commercial and public-space urban trash bins are designed for relatively straightforward assembly, but they rarely come fully put together.
For larger, heavy-duty steel or concrete bins used in parks or city streets, they typically arrive in a few major parts—like the base, the inner liner, the outer shell, and the lid. You'll need some basic tools and maybe another person to help lift and bolt everything together. The instructions are usually clear, and it's more about securing components than complex building.
On the other hand, many resin or plastic bins for semi-public areas like apartment complexes or business districts often come nearly fully assembled. You might just need to attach the lid or drop in the inner bucket. It's often a 5-minute job.
The key factors are size, material, and shipping costs. Fully assembled bins are bulky and expensive to ship, so manufacturers ship them "knocked down" (KD) to save on freight and reduce damage risk. So, while you'll need to do some assembly, it's usually engineered to be a manageable task for maintenance staff, not a complicated DIY project. Always check the product description for "assembly required" or "pre-assembled" before you buy.