• NS&I, which has over 24 million customers in the UK, has faced significant challenges with implementing its digital transformation programme including costs increases, procurement issues and an estimated 4-year delay. 
  • Despite a reset of the programme in 2024, NS&I still does not have a realistic integrated plan in place and lacks capacity and capability to deliver the programme. 
  • The NAO sets out several recommendations for the programme, including developing a plan and reviewing the governance structure. 

The UK’s state-owned savings bank has underestimated the scale of the challenge it has faced in digitally transforming the business – leading to significant cost increases, delays and procurement issues – and must now develop a realistic plan to ensure its transformation programme can deliver the intended benefits for customers and the taxpayer, a new report from the National Audit Office (NAO) has found.1 

National Savings and Investments (NS&I) raises funds for government by borrowing from individual savers, who invest in products such as Premium Bonds, which give savers the chance win tax-free prizes, and tax-free cash ISAs. Customers have collectively invested over £240 billion in NS&I. 

Through its digital transformation programme, which formally launched in 2020, NS&I aims to measurably reduce running costs; support vulnerable and excluded people as a self-service digital business; and deliver its services with greater speed, lower risk and with greater flexibility.2 

NS&I set itself an overly ambitious timetable, resulting in delays and cost increases.3 NS&I now expects the programme to be completed in March 2028 – four years behind schedule – and total costs have risen from £1.7 billion (in 2020) to £3 billion.4 

A weak understanding of the complexity and interdependencies of the system led to problems with procurement of new contracts, delivery and delayed timescales,5 leading to NS&I changing its programme rating from ‘Amber’ to ‘Red’ (indicating that delivery appeared unachievable) and a full programme reset.6  

Since the reset, NS&I has worked to develop an integrated plan for the programme. Although this is not yet complete, NS&I has made efforts to improve relationships with suppliers, identify key risks and finalise a resource management strategy. 

The NAO recommends that NS&I: 

  • develops a realistic delivery plan for the programme, including detailed end-to-end design and aims;  
  • improves its approach to contract management, linking this to how it manages risks and ensuring there are sufficient resource for procuring new suppliers; and  
  • reviews the governance structure required for implementation as well as the system that monitors programme costs and risks. 

The NAO also recommends that HM Treasury clearly lays out expectations of the role of NS&I’s board, as well as its own role in future delivery.  

“NS&I faced complex, long-term technology challenges and saw the ending of the contract with its external supplier as an opportunity to resolve these and transform its business.

“But it underestimated the scale of this challenge and overestimated its ability to deliver its digital transformation programme, which led to significant cost and time increases.

“Since resetting the programme in 2024, NS&I has made progress by identifying the key issues to address. It must now develop a realistic integrated plan to deliver its new operating model and achieve intended benefits for the business, customers and the taxpayer.”

Gareth Davies, head of the NAO

Read the full report

National Savings & Investments’ Business Transformation Programme

Notes for editors

  1. The report will be available on the NAO website from 00:01 on Friday 14 November 2025. 
  2. The Programme formally began in 2020, and aimed to replace the single supplier outsourcing arrangement that NS&I has had with Atos (previously Siemens) since 1999. The arrangement covers most of NS&I’s operations such as communicating with customers and processing payments. NS&I sought to replace its original contract with Atos by running competitions for five separate contracts, all to be awarded and with most services transitioned by the end of Atos’s contract in March 2024.   
  3. NS&I did not allow time for understanding the technical infrastructure, testing or as contingency. See Figure 5 in the report for a timeline between 1999-2025. 
  4. National Savings & Investments’ (NS&I’s) estimate, from 2024 data, of the total cost from 2020-21 to 2030-31, of the Business Transformation Programme (the Programme), including its contract with Atos, and other running costs. 
  5. The business transformation programme aimed to award five new contracts to new suppliers, moving away from single supplier contract model as costs were expected to become unsustainable.  
  6. The programme was rated red by the Infrastructure and Projects Authority (IPA), which reports to HMT, for several years. IPA rated the programme red in its annual reports for 2022-23 and 2023-24, and following this NS&I changed its own rating from amber to red in March 2024. This then triggered an NS&I reset of the programme in July 2024. 

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