Deputy Commissioner James Dipple-Johnstone said:
"Reports of a significant data loss at US-based Equifax and the potential impact on some UK citizens gives us cause for concern. We are already in direct contact with Equifax to establish the facts including how many people in the UK have been affected and what kind of personal data may have been compromised.
"We will be advising Equifax to alert affected UK customers at the earliest opportunity.
"In cyber attack cases that cross borders the ICO is committed to working with relevant overseas authorities on behalf of UK citizens."