NatWest Customers Shut Out of Their Accounts After Major App Outage Linked to Sainsbury’s Bank Migration

NatWest App Chaos Leaves Customers Locked Out of Their Money

By [Aamir Furqan]

Tuesday, 26 August 2025 — London

For thousands of NatWest customers, Tuesday morning started with an unpleasant surprise: instead of checking balances, paying bills, or moving money around as usual, they were met with a cryptic message about Sainsbury’s Bank. The bank’s mobile app and online banking systems went down just as many people were trying to start their day — and for some, it was more than just an inconvenience.

“I just wanted to pay my rent”

From commuters on trains to parents paying nursery fees, the fallout was immediate.

One customer wrote on X (formerly Twitter):

“@NatWest_Help what on earth is happening with the app? I just need to pay my rent, and all I see is something about Sainsbury’s. I’m not even a Sainsbury’s customer!”

Another added that they couldn’t even get past the welcome screen. “It’s like they’ve locked me out of my own money,” they complained.

For many, the problem wasn’t just the app. Because NatWest now requires app-based verification to log in online, even the website was effectively useless. Customers trying to access their accounts on laptops or desktops were blocked too.

What actually went wrong?

The timing of the glitch isn’t random. NatWest is in the middle of absorbing more than one million accounts from Sainsbury’s Bank, after taking over much of its retail business in a deal announced last year. That includes credit cards, personal loans, and billions of pounds worth of deposits.

This morning, however, customers found themselves stuck in limbo. Instead of being able to see their money, many were greeted with a welcome screen explaining that “while we move your account over,” things might look different.

For customers who have never banked with Sainsbury’s, the message was baffling. As one person put it:

“I don’t even shop at Sainsbury’s. Why can’t I log into my NatWest account?”

The scale of the outage

DownDetector, a service that tracks website and app failures, showed more than a hundred problem reports in the first hour alone, with spikes beginning around 9 AM.

The issues weren’t confined to a handful of unlucky people. Reports poured in from across the UK — from London and Manchester to rural Scotland — confirming this was a nationwide disruption.

Desperate workarounds

Some customers found that deleting and reinstalling the app helped them regain access. But for others, it didn’t make a difference.

On X, NatWest’s support team began replying to frustrated customers, asking them to share their full name, postcode, and sort code via direct message. That, however, only fuelled complaints about privacy. One person wrote:

“I’m not about to send my personal details to a random Twitter account. Just fix the app.”

Others simply gave up and headed to local branches, with long queues forming in some towns by mid-morning.

Why it matters

Bank outages aren’t just a nuisance. For many households, especially in a cost-of-living crisis, even a short disruption can mean missed rent, delayed bill payments, or being unable to transfer money for essentials.

A mother in Birmingham told local radio that she was unable to top up her daughter’s lunch card for school. “It’s only a fiver, but without it, she can’t buy food today. I had to drive over with cash at lunchtime.”

Another man said he was stranded on the motorway after realising he couldn’t transfer funds to pay for fuel at a service station. “It’s embarrassing. You feel like your card’s been declined when actually it’s the bank’s fault.”

A history of problems

This isn’t the first time NatWest customers have found themselves locked out. In June this year, more than ten million daily users were hit by an app crash after the bank released a faulty update overnight. The company apologised and fixed the problem within hours, but the memory is still fresh.

According to a report from MPs earlier this year, NatWest has had the worst record for downtime among UK banks in recent years — a total of 194 hours of outages across 13 separate incidents since 2023. Barclays was the next-worst performer with less than half that amount.

For long-suffering customers, today’s problems will feel all too familiar.

Lessons not learned?

Experts say these kinds of failures are becoming more common as banks try to modernise aging systems while simultaneously absorbing millions of new accounts.

Professor Sarah Green, a specialist in financial technology at the University of Birmingham, explained:

“Migrating a million customers from one system to another is like performing open-heart surgery on a patient who’s awake and walking around. It’s incredibly complex, but customers don’t see that. They just see an app that won’t open.”

She warned that regulators are likely to look closely at how NatWest is handling the integration.

What NatWest is saying

At the time of writing, NatWest has not issued a detailed explanation of the outage. On social media, the bank acknowledged the problem and told customers it was “aware and working to resolve the issue as quickly as possible.”

On its website, the official service status page showed “intermittent issues” across the mobile app and online banking platform. Customers were advised to try again later or use telephone banking as an alternative.

What you can do if you’re affected

For those stuck without access, here are the options:

• Reinstall the app: Some users have reported this worked, though not all.
• Telephone banking: Customers can call 03457 888 444 for urgent issues.
• Visit a branch: Traditional counter services are unaffected, but queues are expected.
• Keep records: If the outage causes you to miss a payment or incur a fee, note the details — as this may strengthen any claim for compensation.

Customers losing patience

While technical hiccups are part of modern banking, patience among customers is running thin. With NatWest’s track record, each new outage chips away at trust.

As one angry customer put it online:

“If I can’t rely on my bank app to work in 2025, what’s the point of calling myself a digital bank customer?”

The bigger picture

Banking has gone digital. More than 80% of NatWest’s customers now use the app or website as their main way of managing money. Branch closures in recent years mean many towns have no physical NatWest presence at all, making outages like today’s even more disruptive.

The Sainsbury’s migration was meant to strengthen NatWest’s position in the market. Instead, it risks highlighting just how fragile digital banking can be when systems fail.

What happens next?

If history is any guide, services should return later today. But the real test will be how NatWest explains what happened and what it intends to do differently next time.

For now, customers are left refreshing their apps, crossing their fingers, and hoping their money is still safe — even if they can’t reach it.

Final word

Banking glitches used to mean long queues in branches. Now they mean staring helplessly at a phone screen while bills go unpaid and payments bounce.

For millions, NatWest’s outage was a reminder that no matter how slick the app looks when it works, the technology behind it is still fragile. And in a world where access to your money is everything, fragility is the one thing customers can’t afford.