US credit rating firm’s announcement comes after UK authorities order it to alert British clients of cybersecurity breach.
About 400,000 people in the UK may have had their information stolen following a cybersecurity breach at the credit monitoring firm Equifax.
The US company said an investigation had revealed that a file containing UK consumer information “may potentially have been accessed”.
The data includes names, dates of birth, email addresses and telephone numbers, but does not contain postal addresses, passwords or financial information. Equifax, which is based in Atlanta, discovered the hack in July but only informed consumers last week.
In an effort to provide reassurance, the firm said it was unlikely people would be hit by “identity takeover”. It said it would contact them in writing to offer advice and a free identity protection service to monitor their personal information and data.
Equifax’s president, Patricio Remon, said: “We apologise for this failure to protect UK consumer data. Our immediate focus is to support those affected by this incident and to ensure we make all of the necessary improvements and investments to strengthen our security and processes.”
Equifax alerted the public to the cyber-attack on 7 September. The data of 143 million people was breached in America.
Equifax said its UK systems had not been impacted by the attack but that information on British consumers may have been accessed because of a process failure in 2016 that meant a limited amount of UK data was stored on the US system between 2011 and 2016.
The UK consumer data that may have been stolen does not include “any single Equifax business clients or institution,” it said.
The alert comes after the Information Commissioner’s Office (ICO) ordered Equifax to alert British customers following the firm’s announcement that criminals had exploited a website application to access its files.
Lenders rely on the information collected by credit bureaus such as Equifax to help them decide whether to approve financing for homes, cars and credit cards.
A spokesman for the ICO said: “It is always a company’s responsibility to identify UK victims and take steps to reduce any harm to consumers.
“The Information Commissioner’s Office have been pressing the firm to establish the scale of any impact on UK citizens and have also been engaging with relevant US and UK agencies about the nature of the data breach.
“It can take some time to understand the true impact of incidents like this, and we continue to investigate.
“Members of the public should remain vigilant of any unsolicited emails, texts or calls, even if it appears to be from a company they are familiar with.
“We also advise that people review their financial statements regularly for any unfamiliar activity.
“If any financial details appear to have been compromised, victims should immediately notify their bank or card company. If anyone thinks they may have been a victim of a cyber crime they should contact Action Fraud.”
Equifax said the investigation into the data breach was ongoing and it was working with the Financial Conduct Authority and the ICO.
Cyber-attacks have become an increasing problem for firms that hold a large amount of customer data. HSBC and TalkTalk are among the most high profile British firms to be hit in recent years.