"We know that buy-to-let remortgaging has been more difficult for some landlords since the market adopted those guidelines."
Platform will now use a minimum of 128% rental cover at a notional interest rate of 5.50%.
Buy-to-let mortgage applications that do not meet these criteria will continue to be assessed using a minimum of 145% rental cover at a notional interest rate of 5.50%.
Paul Norcott, head of mortgages and insurance at the Co-operative Bank and Platform, said: "We have been closely following developments in the buy-to-let market since the new PRA guidelines were published, and we know that buy-to-let remortgaging has been more difficult for some landlords since the market adopted those guidelines.
"These changes to our buy-to-let criteria demonstrate that, whilst we remain extremely committed to responsible lending, we also want to take a common sense approach that supports landlords looking for a straightforward like-for-like remortgage."
