A survey of 250 homeowners by Mondaytofriday.com found that almost half (49%) have taken in a lodger just to be able to continue to meet their monthly financial commitments.
Some 55% of these cash strapped landlords use the tax free income to pay bills and 27% to pay their mortgage.
Under the government's Rent a Room scheme, homeowners can earn £4,250 tax-free gross income from renting furnished accommodation in their only or main home.
More than half of those surveyed said they could not cope financially without a lodger and 60% have had a lodger for over a year.
However, not all homeowners who have taken in a lodger spend their monthly income to meet financial commitments. 23% have used the income to make home improvements and 17% have splashed out on a holiday in the last year.
Judy Niner, founder of MondaytoFriday.com, said: "Our survey shows that many homeowners are still struggling, in spite of the more positive news about the wider economy. The £4250 tax free income homeowners can earn from renting out their spare room can help them avoid the gradual accumulation of debt."
The survey also revealed some interesting insights in to the homeowner/lodger relationship. While one in three homeowners (34%) won't share their own bathroom, more than half (56%) will share their favourite coffee mug with their lodger.
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