OneSavings Bank increased its underlying profit before tax by 21 per cent to £167.7m for 2017.
The challenger bank group, whose brands include Kent Reliance and InterBay Commercial, said its loan book had grown 23 per cent to £7.3bn, and its cost-to-income ratio had remained steady at 27 per cent.
Andy Golding, chief executive of OneSavings Bank, said: "I am delighted that OneSavings Bank has delivered another excellent set of results for 2017, whilst successfully negotiating significant regulatory and tax changes in our core buy-to-let market.
"We generated a 21 per cent increase in underlying profit before tax and a 23 per cent increase in underlying basic earnings per share. This was underpinned by strong organic originations, up 14 per cent to £2.6bn, maintaining attractive margins and prudent risk management alongside continued cost efficiency and discipline.
"Despite market sentiment linked to political and economic uncertainty going forward, we entered 2018 with a strong pipeline of new business in our core markets and intend to deploy our proven credit risk and operational competencies to expand our residential and commercial product offerings in 2018."
The bank's net interest margin - the difference between the interest generated from mortgages to that paid out on deposits - remained stable at 3.16 per cent.
Mr Golding said he was expecting net loan book growth in the mid-teens during 2018, with the net interest margin again remaining broadly stable.
He said: "We anticipate a cost-to-income ratio of around 30 per cent for 2018, reflecting the significant increase in the cost of regulation and planned investment in the business to support our growth strategy."
