In the capital the average cost excluding mortgage costs and tax but including void periods is £6,535 per property per year or 32% of the amount they receive in rent.
London is the most expensive region in Britain to be a landlord, research from Kent Reliance shows.
In the capital the average cost excluding mortgage costs and tax but including void periods is £6,535 per property per year or 32% of the amount they receive in rent.
The average UK landlord spends £3,632 per year, which equates to 34% of average rental income.
The North East of England has been identified as the cheapest region, where the average cost is £1,895 per property per year.
Landlords have the lowest running costs in Blaenau Gwent in Wales where costs average £1,495.
John Eastgate, sales and marketing director of OneSavings Bank, said: “With a fifth of UK households living in rented accommodation, landlords play a crucial role in supporting the housing market as they bridge the gap between housing supply and demand.”