Where I live (America, but waste processing is all handled at the local level and policies differ), the landfill has a "resident convenience center" with a bunch of dropoff stations for various types of stuff, along with a big ledge you can toss things over to be sent to the landfill. When you arrive, and attendent will ask and/or look at what you have and tell you where to put it. Sometimes the answer is "you can't dump that for free. Go to the transfer station and pay by the pound".

In theory, there is also an annual wait limit to free dumps, but they can't actually enforce it.