By combining information from online job postings with firm-level financial data provided by Orbis, as well as firm-level merchandise trade data, this paper seeks to get a deeper understanding of the characteristics and performance of data-intensive firms in the United Kingdom since 2015. Data-intensive firms are defined here as firms which are hiring data-related skills. One key contribution of the analysis is to match in a more efficient way the two data sources, Lightcast and Orbis, which are now used extensively in the economic literature. Both the number and the share of data-intensive firms increased sharply in the United Kingdom from 2015 to 2021, with a peak in 2020. The number of highly data-intensive companies and data-intensive multinationals (MNEs) display the same pattern. A large share of data-intensive firms operate within the information and communication industry and are predominantly located in the Greater London area, especially in London itself. Those firms tend to employ more staff and are more capitalised than non data-intensive firms. They are on average more productive, generate more revenues and trade more in foreign markets. While data-intensive firms can be found in all firm size groups, the firms displaying on average the highest level of data intensity were medium sized in 2015 but are now small sized. In terms of international trade, UK dataintensive firms are, generally, more export intensive than non data-intensive firms, but estimates vary across industries.