Such has been its level of growth, the bank expects to up its book by more than the 29% recorded in 2014.
OneSavings Bank offers residential, buy-to-let and commercial mortgages, along with secured loans and development finance.
Andy Golding, chief executive of OneSavings Bank, said: “I am very pleased with our 2015 performance to date.
“We received record levels of new business applications during the third quarter and remain confident in delivering on all of our stated financial objectives through to the end of 2016.”
It is believed the bank has profited from the strengthening buy-to-let market in 2015, with low interest rates and a lack of housing supply resulting in demand so strong that the government felt forced to intervene in the Budget by cutting the amount of mortgage tax relief landlords can claim to 20% by 2020.
