The ‘Rent-A-Room' entrepreneurs collectively accumulate over £3.9 billion per year in rental payments - an average of £182 per month.
The research shows that there is currently a potential £52 billion of rental income to be made in the UK from renting out spare rooms. However, nine out of 10 people (92%) with a spare room still choose not to rent it out though there are 3.7 million homeowners who have considered doing so.
More than a third (35%) of those who rent out a spare room do so to help out a friend or family member. A further one in five (18%) do so because they need the additional income to meet their outgoings whilst 17% need the money to supplement their disposable income.
Homeowners in the South of the UK accumulate the most amount of rental income from their spare rooms. One in seven (14%) people in the South West and one in ten (11%) of those in the South East rent out a spare room. Meanwhile Brits living in the East Midlands (4%) are less enthusiastic about taking in a lodger.
Three quarters of UK homeowners would not consider renting out a spare room with more than half of them (52%) not wanting to do so because they don't want a stranger in their home. One in three Brits (33%) keep the spare room free purposely for guests, 21% do not need the additional income and 21% use the room for storage.
Of the one in four (25%) Brits who would consider renting out their spare room, 11% would do so if they needed to financially and 15% would rent out the room if a friend or family member needed it. Some 7% would consider it if they could find an appropriate tenant and 4% would do so if they were able to make decent money from it.
Phil Cliff, director of Santander Mortgages, commented: "It's interesting to see that so many Brits are weathering the economic storm and showing such entrepreneurial spirit by renting out spare rooms in their home. This can make a real difference to how much money you have left at the end of the month. However anyone with a mortgage who is renting out a room should speak to their mortgage lender first to check they aren't breaching the terms and conditions of their agreement."
Matt Hutchinson of Spareroom.co.uk believes it is time the Government changed the rent-a-room tax threshold.
"With so many homeowners renting out their spare rooms, it's time for the Government to think about raising the rent-a-room tax-free threshold, which has not changed since 1997,” he said.
"Tax breaks available to homeowners looking to make some extra cash by taking in a lodger need to take into account rising rents and the soaring cost of living.
"The average annual room rent for the whole of the UK is £4,560 and in London it's £7,200, well above the current rent-a-room relief threshold of £4,250.
"This survey carried out by Santander underlines how many homeowners rely on lodgers for vital extra income, but I'm sure many are put off by the prospect of having to fill out a self-assessment form for taxable earnings above the current threshold."
