National Savings and Investments, the Government-owned provider of Premium Bonds, has confirmed the rollout of a new mobile app service as part of its wider transformation programme. The update comes as the organisation faces criticism from MPs over delays and rising costs linked to its digital modernisation plans.
Premium Bonds remain one of the UK’s most widely held savings products. Each £1 Bond is entered into a monthly prize draw, with odds currently set at 22,000 to one. Prizes range from £25 to £1 million, with two £1 million jackpots awarded every month.
However, recent attention has focused less on prizes and more on NS&I’s long-running technology upgrade.
Programme
NS&I has been working on a digital transformation programme for five years. The aim was to modernise its systems, improve efficiency and reduce long-term operating costs.
By March 2024, £111 million had been spent on the project. According to the Public Accounts Committee, this figure is broadly equivalent to four years’ worth of Premium Bonds £1 million jackpot prizes.
In 2024, the estimated total cost of the programme rose to £3 billion. This represents an increase of £1.3 billion compared with the original 2020 forecast. The committee has warned that further increases may occur once the current reset phase is complete.
The project was previously known as Project Rainbow, a name that has since been retired.
Criticism
The Public Accounts Committee, which scrutinises public spending, described the programme as a “full-spectrum disaster” in its report.
Sir Geoffrey Clifton-Brown, chair of the committee, said the project had gone significantly off track. He stated that both the committee and, at times, the Treasury struggled to obtain accurate information on costs and progress.
The report also raised concerns that NS&I lacked the necessary in-house expertise at the outset. It said the organisation relied heavily on external consultants and had not yet delivered meaningful benefits despite significant expenditure.
The committee has requested further detail on how the reset programme will operate and what the final costs are likely to be.
Response
In response, NS&I said it welcomed the committee’s findings and recommendations.
A spokesperson stated that the business transformation programme remains central to delivering cost-effective finance for the Government and improved services for customers. The organisation said it is reviewing options to strengthen programme delivery and will provide further updates in due course.
NS&I acknowledged that rebuilding 25 years of complex IT infrastructure has proved more challenging than initially expected.
Rollout
Despite the broader reset, NS&I confirmed progress in certain areas.
In 2025, around 750 customer service agents and 350 back-office staff were transferred to a new supplier. The organisation has also begun rolling out its mobile app to operate under its new partner’s platform, ahead of further upgrades.
In addition, NS&I said it has launched the technical architecture linking its new multi-supplier operating model. This structure is intended to support the next stage of system improvements.
The mobile app rollout is seen as a key part of improving digital access for customers managing Premium Bonds and other NS&I products.
Premium Bonds
Premium Bonds continue to attract strong interest from savers. Instead of paying traditional interest, Bonds offer monthly prize draws funded by a prize rate.
Key features include:
| Feature | Detail |
|---|---|
| Minimum investment | £25 |
| Maximum holding | £50,000 |
| Prize odds | 22,000 to 1 per £1 Bond |
| Top prize | £1 million |
| Monthly jackpots | Two |
While large prizes receive the most attention, the majority of winnings are smaller amounts such as £25 or £50.
Funding
NS&I plays a broader role in Government financing. The organisation stated it is on track to raise £13 billion this year to help fund public services. It estimates this approach will deliver more than £2 billion in savings compared with raising equivalent funds through government bonds, known as gilts.
Over the past three years, NS&I products have raised £31 billion for the Government. Using its value indicator measure, the organisation said this has delivered £3.2 billion in savings to taxpayers when compared with gilt issuance.
The value indicator compares the cost to the Treasury of raising funds via NS&I products against the cost of borrowing through the gilt market.
Outlook
The transformation programme remains under review, with the reset process ongoing. While some technical milestones have been completed, significant questions remain over final costs and delivery timelines.
For customers, day-to-day access to Premium Bonds and other NS&I products continues as normal. The rollout of the updated mobile app forms part of a longer-term effort to modernise services.
Further updates on the programme’s structure, cost controls and implementation are expected once the reset phase concludes.
FAQs
What are Premium Bonds odds?
22,000 to 1 for each £1 Bond.
How many £1m prizes monthly?
Two £1 million prizes each month.
How much has the project cost so far?
£111 million by March 2024.
What is the estimated total cost?
Around £3 billion as of 2024.
