Amateur landlords face tighter borrowing rules and stricter affordability tests under Bank of England plans to crack down on buy-to-let lending.
Financial regulators want lenders to make income checks more stringent for buy-to-let investors and test whether they can still afford their regular repayments at higher interest rates.
It comes amid fears Britain's booming buy-to-let market is overheating, with warnings that surging levels of lending to landlords pose a risk to the property market and financial system.
The Bank of England estimates that the latest plans could cut new approvals for buy-to-let mortgages by about 10% to 20% by the mid 2018.
Meanwhile, recent figures showed a rush by landlord investors to beat a stamp duty hike on 1 April, sending demand for homes surging to a 12-year high in February.
The new three percentage point stamp duty increase on the purchase of second homes is part of the strategy to prevent a bubble in the market.