Yes, it is generally legal to sleep in a roof tent in the UK, provided your vehicle is parked legally and you are not in violation of local bylaws. The legality is often a matter of "parking vs. camping." In England, Wales, and Northern Ireland, "wild camping" (including in a vehicle) technically requires the landowner's permission. However, sleeping in a roof tent while parked in a designated lay-by or public car park for a rest during a long journey is often tolerated as long as you are not "setting up camp" with chairs, tables, and awnings. In Scotland, the law is more permissive; under the Scottish Outdoor Access Code, you can camp on most unenclosed land, though this primarily applies to non-motorized access. For motorized vehicles with roof tents, the "Stay the Night" initiatives in some National Forests provide legal spots for a fee. The key in 2026 is discretion: if you are parked legally on a public road and stay inside your "footprint," you are usually within the law, but always check for "No Overnight Parking" signs.