That's a great and very practical question! In the vast majority of cases, standard outdoor trash bins or garbage cans that you purchase from hardware stores, home centers, or online retailers do not come with liners included. The bin itself is typically sold as a standalone product.
You will almost always need to purchase trash bags or liners separately. This is for a few good reasons: it allows you to choose the bag size, thickness (mil), and material that best fits your specific bin and type of waste. Some people prefer standard bags, others want heavy-duty contractor bags for yard waste, or scented bags for kitchen scraps.
However, there are a few exceptions. Some premium or specialized compost bins might include a starter supply of compostable bags. Also, if you are renting a dumpster or a specific waste collection system from a municipal service or private company, liners might be part of the service package—but this is rare for standard home use.
So, the safe bet is to plan on buying liners separately. When you get your new bin, check the product's dimensions (height and gallon capacity) to ensure you buy the correct size bags for a perfect fit. This prevents bags from slipping down into the can and makes taking out the trash much easier.