The lender has braced for an impact on loan defaults by bumping up provisions.
Santander reported gross mortgage lending in the nine months to October of £28.2bn in a strong market, up from £25.2bn in the same period last year.
However, £256m was set aside in credit impairment charges, up from £170m at the same point last year.
Santander said it had not seen a “material deterioration” in the mortgage book to date.
But underlined that a backdrop of higher inflation, energy prices and increased interest rates could affect customer’s abilities to make repayments.
Off the back of higher impairment charges, adjusted profit before tax fell by three per cent to £1.64bn from £1.7bn in 2021.
The bank has proactively contacted more than 1.6m customers deemed to most impacted by the cost of living crisis to highlight the support on offer.
Santander said it expected mortgage lending to be broadly in line with market growth this year.
Mike Regnier, UK chief executive, said: “Many of our customers remain worried about the impact of the cost of living, and they are looking to us to help them navigate this challenging environment.
“As one of the UK’s leading mortgage providers, we particularly understand the concerns of existing mortgage customers, first time buyers and especially those whose fixed rate mortgage is about to come to an end.
“So we are providing advice and guidance on how households can manage their mortgage, such as exploring options around length of term.
“We are also continuing our programme of proactively contacting customers who are struggling, to offer help with managing their finances and energy costs.
“In this environment, we have maintained a focus on how we can deliver more for our customers with products that deliver real value.”
He added: “These are a set of results reflecting the hard work of our people, but they also demonstrate the continued importance of taking a prudent approach to risk and maintaining a resilient balance sheet.
“While we have seen no material deterioration in our mortgage book to date, we have increased our provisions. Looking ahead it is clear that the ongoing inflationary pressures, increased energy prices and impact on economic activity will mean the service and support we provide our customers and businesses will continue to be critical.”
