Executing on a bold transformation vision beyond the legacy
OSB Group, a UK-listed specialist mortgage lender, has accelerated its innovation journey by modernising its technology landscape with Mambu, enabling simplified operations, and customer-centric digital savings and mortgages.
As of 31 December 2025
- £0.6
- billion net loan book
- £0.3
- billion retail deposits
- c.0
- employees
OSB Group
About the customer
OSB Group is a UK-listed specialist mortgage lender, dedicated to supporting underserved segments of the market. They specialise in lending and retail savings through well-known brands, focusing on specific sub-segments, including Buy-to-Let, Residential and Commercial.
The bank’s 6 lending brands, including Rely, Precise, and InterBay, serve a diverse range of customers and needs.
With £25.3 billion in retail deposits and a Common Equity Tier 1 (CET1) ratio of 15.8% as at 31 December 2025, OSB Group continues to be a strong player in the UK’s mortgage and savings sectors.
The challenge
Future-proof tech landscape
To keep pace with evolving market demands and growth plans, OSB Group, a growing specialist lender with a rich history, proactively recognised the necessity of upgrading its systems.
The lender embarked on a comprehensive five-year transformation journey in 2022 to reimagine its vision, develop a strategic roadmap for operational modernisation, build future-proof banking capabilities and deliver a robust, scalable and customer-centric platform.
OSB Group needed a core solution that would facilitate easy integration of new technologies and rapid delivery of customer-centric financial products in a competitive and highly regulated market.
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