The residential, second charge and buy-to-let lender’s net loan book grew 5% in the first three months of the year with net loans and advances increasing by £283m to give a total loan book of £6.22bn.
It said its strong financial and operational performance last year had continued in the first quarter of the year.
The group, which includes Kent Reliance and Prestige Finance, has also drawn a total of £451m under the Term Funding Scheme (TFS) and reduced its Funding for Lending Scheme (FLS) withdrawal to £525m.
One Savings Bank CEO Andy Golding said he was delighted with the performance of the business so far this year.
“We achieved £599m of organic origination at attractive margins during the first quarter, and enjoyed exceptionally strong levels of new mortgage applications, a trend that has continued into Q2,” said Golding.
“This further demonstrates the strength of our specialist capabilities, which line up directly with the continuing professionalisation of the buy-to-let market. We remain confident of achieving at least mid-teens net loan book growth in 2017.”