Lloyds bank reveals IT glitch affected almost half a million customers

Almost half a million Lloyds, Halifax and Bank of Scotland customers saw other people's transactions or had their own data shared in a recent IT issue, the bank has revealed.

But in a letter responding to the Treasury Select Committee's enquiries about the incident published on Friday, Lloyds said it had affected up to 447,936 customers.

Committee chair Dame Meg Hillier said it reflected modern banking's trade-off in enabling convenience but also "unpredictable errors".

"Modern banking methods mean we can now perform a variety of tasks on our phones in a matter of seconds, and almost anywhere," said Dame Meg.

"What this incident brings into focus is the fact that there is a trade-off."

She said interacting with banks online more means consumers "place our faith in technology which can suffer unpredictable errors" - adding it was important this was made clear to customers.

"That's why my Committee continues to push banks to be transparent when things go wrong," Dame Meg added.

The letter, from Lloyds Banking Group's consumer relations boss Jasjyot Singh, said its findings to date showed 114,182 customers had clicked on other people's transactions when they appeared in their own app interfaces.

It added they may have then been shown "detailed information such as account details, national insurance numbers and payment references".

"Although it was fixed promptly, we are extremely sorry the incident happened and we understand the questions it will have prompted," Singh wrote in the letter published on Friday.

"We have immediately investigated how the incident occurred."

According to Lloyds' letter, some customers may have also seen transaction information related to people who were not customers of any of its banks, such as in instances where payments had been made by a Lloyds Banking Group customer to another bank.

Singh said the company would "cooperate fully" with financial regulators including the Financial Conduct Authority (FCA) and the UK's data watchdog, the Information Commissioner's Office (ICO).

The ICO said at the time it was "making enquiries" with Lloyds about the matter.

The FCA had told the BBC in a statement it expected "firms to protect customer data and be able to respond to and quickly recover from disruptions".

At the time of the incident, one affected user, Asha, said she had panicked after seeing unknown transactions on her app - especially as their figures appeared to match the totals of her back account.

"I assumed I was hacked or a fraud had went on," she told the BBC.

"I genuinely thought someone had cloned my details - one transaction was by someone who bought a car. I thought they'd spent £8,000 of my money."

She added the experience had left her feeling "almost traumatised".