Why the NS&I App Keeps Crashing: The £3bn IT Disaster Explained

If you've ever tried to check your Premium Bonds on draw day only to find the NS&I app frozen or the website unresponsive, you're not alone. Parliament's spending watchdog has now confirmed what millions of frustrated users suspected: NS&I's IT systems are in crisis, and it may take until 2031 to fix them.

What the PAC Report Found

The Public Accounts Committee (PAC) published a damning report on 13 February 2026. Chair Sir Geoffrey Clifton-Brown described NS&I's business transformation programme as a "full-spectrum disaster" that has exposed taxpayers to "unacceptable risk".

The programme, originally called Project Rainbow, was launched in 2020 with ambitious goals: modernise NS&I's operations, reduce running costs, and replace Atos — the French company that has run NS&I's banking services and IT infrastructure for 27 years.

Instead, the project has become a case study in government IT failure:

• Rated "unachievable" two years running: In 2022-23 and 2023-24, the programme was rated "red" — meaning successful delivery appeared unachievable
• Costs more than doubled: The original £1.3bn budget has ballooned to £3bn with "little transformation" actually delivered
• Complete deadline failure: By March 2024, the original completion date, "none of the new services had been modernised or were live"
• Core banking engine untouched: The PAC described replacing NS&I's core banking system as "extremely high risk" — and the main work hasn't begun
• Atos contract may extend to 2031: Rather than replacing Atos, NS&I may need to extend the contract for another five years
• Still no plan after five years: NS&I still has "no agreed and approved integrated plan" and "no idea of eventual cost"

Why This Happened

The PAC report identifies a catalogue of failures:

No understanding of complexity: NS&I launched multiple procurements and planned to deliver four transitions in parallel "with no understanding of the risks this was exposing the organisation and its customers to." They awarded contracts before understanding dependencies between systems.

Overambitious from day one: NS&I tried to split operations from a single supplier (Atos) into a multi-supplier model on an aggressive timeline. When asked what evidence led them to conclude this would be easier than managing one large contract, NS&I "had no answer."

Consultant dependency: NS&I spent £43m on external consultants but still lacked the right skills and expertise internally. The PAC noted there was "no agreed and approved integrated plan" despite this spending. Remarkably, when asked how much had been spent on the programme, NS&I said it had "the right data" but was finding it challenging to "present" it.

Poor oversight: The Treasury announced another £109m for the programme in January 2026 despite NS&I being unable to say how much had actually been spent to date. As PAC chair Sir Geoffrey Clifton-Brown put it: "Neither this Committee, nor at times the Treasury itself, could gain an accurate sounding on costs and progress."

"Good news" culture: The PAC found that NS&I has a culture "which can result in decisions not being made and disagreements not resolved." When asked about this, NS&I's leadership described a "can do" attitude — to which Sir Geoffrey responded: "The results so far would very much demonstrate that the reality is closer to 'can't do.'"

Slow to act on advice: External organisations reviewing the programme told the NAO that NS&I was "sometimes or often slow to act, or did not act at all, on advice." When asked if leadership had learned from the issues, NS&I could only offer that they had "continued to operate the organisation as a whole despite the delays."

For context on how badly this compares: the Bank of England's early settlement scheme was renewed in a similar timeframe, on time and on budget, at a cost of £431m. NS&I's programme has cost seven times more and delivered far less.

The Core Banking Engine Problem

The most concerning element is the replacement of NS&I's core banking engine — the system that manages all products including Premium Bond prize draws. The PAC describes this as "extremely high risk" because it affects customer data for 25 million people holding over £240bn.

NS&I acknowledged that when it replaces the banking engine, data migration would be a "huge consideration" needing to be managed "in minute detail" — but gave no details of how they would actually do this. The main work hasn't even started, and NS&I's contract with Atos to run the current engine expires in 2028.

Atos: The Company Behind NS&I's Systems

Atos, the French IT company running NS&I's infrastructure, has been in place since 1999 — over 25 years. The company suffered financial distress in 2024 and has been restructuring. NS&I told the PAC it had needed to spend "time, energy and resources developing continuity plans" because of Atos's difficulties, diverting attention from the transformation.

Despite NS&I's original plan to move away from Atos by March 2024, the PAC report suggests the contract may now extend until 2031. NS&I will continue to rely on Atos "until at least 2028" — and likely beyond.

What This Means for Premium Bonds Holders

However, users should expect:

• Continued draw day crashes: The first working day of each month will likely remain problematic as millions of users overwhelm aging infrastructure
• Slow app performance: The NS&I Prize Checker app and website run on systems that weren't designed for modern mobile usage patterns
• No quick fixes: With the core banking replacement years away, incremental improvements are the best case scenario

Alternatives When NS&I Systems Fail

When the NS&I app crashes on draw day — which happens most months — you don't have to wait for their systems to recover. Our Prize Checker uses different infrastructure and typically remains available when NS&I's official systems are overwhelmed.

You can also check prizes by:

• Using Amazon Alexa: "Alexa, have my Premium Bonds won?"
• Calling NS&I on 08085 007 007 (though phone lines are often busy on draw day)
• Waiting until later in the day when traffic subsides

What Happens Next

The PAC's conclusion is blunt: "We are not confident that NS&I will deliver the Programme successfully."

NS&I has said it "welcomes" the PAC report and its recommendations, adding that the transformation programme is "key to NS&I continuing to deliver cost-effective finance for government and the services customers want." They promised to provide an update on improved delivery "in due course."

The committee has demanded NS&I produce a realistic plan within six months, and stop trying to "compress work" to meet unrealistic deadlines. But given that NS&I still has no integrated plan after five years, and the PAC found their confidence "is very much part of the problem," users shouldn't expect rapid improvement.

For Premium Bonds holders, the practical takeaway is simple: NS&I's systems will remain unreliable for the foreseeable future. Plan accordingly, especially on draw day.

Disclaimer: This article is for informational purposes only and does not constitute financial advice. We are not affiliated with NS&I. Information based on the Public Accounts Committee report and press release published 13 February 2026.