Nottingham-based (but with a Dublin HQ) data specialist Experian began life as the credit-checking arm of 70s catalogue shopping business Great Universal Stores. It now provides fraud and credit ratings checks to both businesses and individuals alike, as well as big data analytics services and market research products. It has 17,000 employees in 37 countries and holds data on some 870 million individuals worldwide. Revenues from ongoing activities in H1 2016 rose 5% to $2.23bn, and its email marketing business is for sale. CEO Brian Cassin has been in charge since 2012.
Image source: Experian