Around 400,000 people in the UK are speculated to have been affected by the recent Equifax hack that hit more than 143 million citizens in the US. The credit monitoring company divulged the number following an investigation.

Equifax consumer information of those living in the UK "may potentially have been accessed" that includes names, dates of birth, telephone numbers and email addresses. The data breach was first discovered by the company in July but only informed clients last week.

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The Atlanta company reassures consumers that stolen information will not be used for identity theft. Postal addresses, passwords and financial information have not been stolen. Nevertheless, Equifax has vowed to reach out to each client and offer a free identity protection service to monitor their personal data.

"We apologise for this failure to protect UK consumer data," says Equifax president Patricio Remon in a statement. "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."

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Remon has noted that the attack targeted US clients, stealing the data of about 143 million people. The Equifax systems in the UK had not been impacted but around data of about 400,000 people in the country "may have been accessed".

He further stated that the UK consumer data that may have been stolen does not include "any single Equifax business clients or institution".