Atom bank lifted annual mortgage completions 20% to £1.6bn as it introduced an app home loan retention feature and trimmed offer times.

The digital bank’s loan book lifted 33% to £3.1bn in the year to the end of March.

The firm points out that a new in-app mortgage retention process for existing customers saw retentions jump 350%, while the median speed for offer times fell by 24 hours to five days, over the last 12 months.

“There’s plenty more scope for growth and improvement in the year ahead both in terms of originations and retentions,” said Atom chief executive Mark Mullen in the lender’s annual report published today.

The bank’s portfolio “predominantly” consists of owner-occupied loans, but also includes £612m of buy-to-let lending to professional landlords, up from £212m over the period.

The business swung to a pre-tax profit of £6.7m, from a £10.1m loss a year ago.

Mullen added: “This has been our best year yet at Atom bank.

“We have achieved profitability across all measures, grown our loan book significantly, maintained robust credit quality, avoided fraud losses altogether, kept our costs tightly controlled and enhanced our already industry-leading customer experience metrics.

“UK banking remains dominated by players with low growth, high costs and indifferent customer service.

“We remain entirely focused on serving the needs of borrowers and savers, without the soaring costs and operational complexity of transactional banking products like current accounts.”