The Rent a Room scheme allows homeowners to earn up to £7,500 each year tax-free by renting out a room to lodgers. In order to qualify, the room must be in their main home and offered on a fully furnished basis.
Certain homeowners will need to obtain permission from their mortgage provider (eg if there is a relevant stipulation in the contract regarding lodgers). People renting a home may be able to sub-let a spare room under the Rent a Room scheme but they will generally need permission from their landlord.