New research reveals that Brits pocket £3.3 billion per year by renting out their spare room.
That represents an estimated 1.7 million (nine per cent) UK homeowners, up from six per cent in 2011.
Key findings in the Santander Mortgages study include:
Nearly three-quarters (74 per cent) of homeowners have at least one spare room in their home that currently is either rented out or has no-one living in it.
There is currently a potential £38.9 billion of rental income to be made in the UK from renting out spare rooms.
More than one-third (35 per cent) of those who rent out a spare room do so to help out a friend or family member.
A further 11 per cent do so because they need the additional income to meet their mortgage payments and outgoings.