Your local council is required to offer disposal services which allow you to get rid of a range of items, and these usually come in the form of disposal centres or ‘tips’. These places accept all sorts of household waste, which includes bulky furniture (including your sofa). If you’re not sure where your local recycling centre is, you can use this useful location search tool.
However, taking your sofa to the tip can be difficult to do largely due to the size and weight of sofas – especially if you own a large L-shaped unit! Most places ask you to break down the piece of furniture before disposing of it to save some room which means having to remove all cushions, cut the wooden frame, and break it up into more manageable pieces.