Nationwide has reported a fall in profits in its half-year results on Thursday.

In the six months to September 30, the building society reported a 17.8% fall in pre-tax profits to £516 million compared to the same period last year.

Nationwide has put the fall in profits downs to a £135 million cost for asset write-offs and technology investments.

Investments in technology have been in order to fend off competition from rival Monzo and are expected to save the group £200 million a year from 2023.

The lender has said that it is on track to save £100 million for the full year.

“Our first-half profits were lower than last year because we have chosen to increase our investment in the future of our Society. As a mutual, we do not judge our success by profit growth alone, but by how we manage our profits to serve our members’ interests,” said Joe Garner, Nationwide’s chief executive.

“We do that by maintaining the high-quality service and excellent value products our members prize today, while also investing in building new propositions, services, and skills, so we can meet members’ future needs.”

“The strength of our business means we are well placed to invest confidently in the future of the Society, and we have committed to invest an additional £1.3 billion over the next five years to transform our technology estate and capabilities. This will take our total investment over the next five years to £4.1 billion and will ensure the Society makes the most of the opportunities ahead. We will develop new propositions, further enhance our service, simplify our operations and build new skills for the future.”

“We continue to lead our high street peer group for customer satisfaction by a significant margin. We protected savers and rewarded loyal members, delivering £330 million in member financial benefit through better rates, fees and incentives than the market average over the half year.”

“The special rate ISA, available exclusively to our loyal members, contributed to a £5.1 billion rise in deposits. We continued to support first time buyers, helping a record 40,500 into a home of their own – one in five of all first-time homeowners. And more people are choosing Nationwide for their everyday finances, with almost 400,000 current accounts opened with us so far this year,” he added.

Notes issued by the group (LON: NBS) are trading -10.82% (0854GMT).