The UK information regulator is examining an IT glitch that enabled some customers of Lloyds, Halifax and Bank of Scotland to see other users’ transactions when they logged into their banking app.

The Information Commissioner’s Office (ICO) said it was “aware of an incident affecting some online banking services” and that it would make inquiries.

Worried bank customers posted on social media they feared they had been hacked when they checked their account and were greeted with the details of other people’s finances, including cash withdrawals and benefits payments.

In a Facebook post, the consumer champion Martin Lewis said people had been messaging about “being shown other people’s transactions”.

In response, the founder of MoneySavingExpert was inundated with close to 2,000 comments from worried bank customers.

In a post, Shirley Finlayson said that, when she logged into the Bank of Scotland app, she “saw quite a few transactions, one going back to 2024, the payments going out showed all the details of the person receiving it, name, bank account/sort code”.

Another user, Jill Steel, said that when she logged into her Lloyds app she had been able to see the financial details of 30 people. “Can see names plus corresponding account numbers and sort codes. NI numbers if they’re receiving any benefits.”

A spokesperson for Lloyds Banking Group, which owns the three banks said the incident had been quickly resolved. “We’re sorry that some customers experienced an issue viewing transactions in the app for a short time this morning. We’re looking into what happened,” they said.

Organisations have to decide whether it is necessary to report a data breach to the ICO and have 72 hours to make their mind up after the incident occurs.

Last year, there were a series of IT failures that affected UK bank customers, leading to concerns about the robustness of systems. Lloyds, TSB, Nationwide and First Direct customers were among those affected by technical issues on payday in January and February 2025.

The outages come amid a wider push towards digital banking by lenders, which are facing growing competition from online-only lenders such as Monzo and Revolut, as well as JP Morgan’s Chase UK.

Lenders that once dominated the high street have continued shutting branches, in a move they say is justified by dwindling use of in-person banking.

It has led to thousands of closures, with the number of branches across the UK falling from roughly 10,565 in 2014 to 6,870 by 2024, according to British Banking Association and Office for National Statistics data.