James Delaney,BBC Scotlandand
Liv McMahon,Technology reporter
An investigation has been launched after some customers using Lloyds Bank, Halifax and Bank of Scotland apps were able to see other users’ transactions on their accounts.
The glitch meant they were able to view charges and payments made by other people.
A spokesperson for Lloyds Banking Group, which owns all three banks, apologised for the issue and said the incident had been resolved.
It is unclear how many users have been affected – but one woman told BBC News she was able to see the accounts of six different users on the Bank of Scotland app, including some National Insurance numbers, over a 20-minute period.
She said these included transactions from a pub in Newcastle, 154 miles from her home in Kirkcaldy, Fife, fees for using one card abroad and wage payments from a company based in England.
The 55-year-old – who didn’t want to be named – also reported being able to view benefits payments from the Department of Work and Pensions (DWP), which use the National Insurance numbers of recipients as a payment reference.
She said: “There were transactions from Waitrose, there isn’t a Waitrose near us.
“I kept logging out and back in, and every time the details changed.
“I can see another person’s bank account, he got paid £6,000 yesterday. Others, I can see their benefits payments, their National Insurance numbers, I can see where they work, almost their whole identity.”
Similar issues have been flagged to Lloyds Bank, Halifax and Bank of Scotland by customers on social media.
“This morning we incorrectly showed transaction information from some accounts to other customers in Internet Banking and the mobile app,” the Lloyds Bank account on X has told some concerned users.
“We’re sorry this happened. This issue was quickly identified and resolved.”
Outage tracking website Downdetector saw a spike in reports of issues with the Halifax and Lloyds apps between 07:00 and 09:00.
A smaller spike was reported on the Bank of Scotland app, according to the website.
Lloyds Banking Group says it is the UK’s largest retail and commercial banking provider, with 26 million customers.
An ‘unusual’ error
This is not the first time the Lloyds Banking group’s apps have experienced issues.
Those glitches saw thousands of reports from users to platform outage monitor Downdetector, and calls from consumer groups and officials for banks to boost their resilience.
Those banking app issues left customers unable to view their own recent transactions or make payments – as opposed to exposing the financial details of other people.
Markos Zachariadis, professor of financial technology and information systems at the University of Manchester, told the BBC it was an “unusual” incident, and suggested it might be related to the growing sophistication and popularity of digital banking.
“As data openness becomes greater and more complex architectures arise such issues can become even greater,” Prof Zachariadis said.
The Lloyds Bank account on X has sought to reassure some customers expressing concern about the security of their accounts or information.
“We can assure you that nobody had access to your accounts,” it wrote in posts seen by BBC News.
“We’re currently reviewing what happened to ensure this cannot occur again. Protecting our customers’ personal information and account security remains our priority.”
The BBC has approached the UK’s data watchdog, the Information Commissioner’s Office (ICO), for comment.
Lloyds has not responded to questions from the BBC about how many customers have been affected by the issue or whether it has contacted the ICO or any other UK regulators following the incident.