Background to the report

National Savings & Investments (NS&I) plays a key role in raising finance for the government through the retail savings market. It does this by borrowing on behalf of the government from retail investors through the issue and sale of savings and investments products such as Premium Bonds. As one of the largest savings organisations in the UK, it has some 25 million customers, who have collectively invested over £240 billion with NS&I.

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NS&I is a non-ministerial government department and an executive agency of the Chancellor of the Exchequer. HM Treasury sponsors NS&I and oversees its operations, including through a representative on the NS&I Board, which operates in an advisory capacity to the NS&I Chief Executive, who is also its accounting officer.

In 2020, NS&I formally began its Business Transformation Programme, originally called Project Rainbow. Through the programme, NS&I aims to:

  • measurably reduce the cost of running NS&I;
  • make NS&I a self-service digital business with support for the vulnerable and excluded; and
  • enable NS&I to “deliver more nimbly, reduce risk and enhance scalability”.

In 2022-23 and 2023-24, the programme was rated ‘red’ in the Infrastructure and Project Authority’s (IPA) annual reports. IPA defines this as: “Successful delivery of the project appears to be unachievable. There are major issues with project definition, schedule, budget, quality and/or benefits delivery, which at this stage, do not appear to be manageable or resolvable. The project may need re‑scoping and/or its overall viability reassessed.” A Committee of Public Accounts report in March 2024 highlighted the significant delays to the Programme due to a poorly executed procurement process.

Scope of the report

This report sets out what has happened on the Programme so far to lead to the reset, the progress that NS&I has made in addressing the issues and risks facing the Programme, and what NS&I still needs to address. It examines:

  • Programme progress compared to the original plans;
  • how NS&I set up the Programme and commercial approach and how it is approaching the Programme reset; and
  • how NS&I has sought to learn and apply lessons to inform the Programme, and how it will manage the remaining Programme risks and issues.

Given the Programme’s progress we do not conclude on value for money, nor does the report consider NS&I’s wider operational systems, or performance in managing customers’ savings and offering savings products.

Conclusions

NS&I faced complex, long-term technology challenges and saw the ending of its contract with Atos as an opportunity to resolve these and transform its business. Replacing a 25-year incumbent supplier with multiple suppliers was always going to be a challenge. NS&I underestimated the scale of this challenge and overestimated its ability to deliver the Programme, despite warning signs about its lack of skills and capability and the complexity of disentangling a highly integrated IT system.

The absence of an end-to-end solution and integrated plan has led to programme delays and commercial challenges. The Programme was not sufficiently thought through before key decisions were made, which led to significant cost and time increases.

Since mid-2024, NS&I has identified several key programme and contractual issues. It is in the early stages of working out how to deal with the many complexities and issues it faces. It has brought in external expertise to support systems integration and develop an integrated plan with new milestones, which will necessitate further renegotiation of its current supplier contracts.

NS&I will need to reconsider the scope and priorities of the Programme to remain within its budget that has now been fixed by HM Treasury. The Programme remains highly complex and it is essential that NS&I develop a realistic integrated plan to deliver its new operating model and the intended benefits for the business, customers and the taxpayer.

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Publication details

Press release

View press release (14 Nov 2025)

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