The Research Excellence Framework (REF) 2014 is a nationwide initiative designed to assess the quality of research in UK higher education institutions (HEIs). For the first time, REF 2014 introduced the wider impact of research, alongside the quality of research and the vitality of the research environment, into the assessment of research excellence in UK HEIs. The impact of research is weighted at 20% of the total assessment for 2014, as it is important to recognise wider societal benefits resulting from publicly funded research. Understanding how the impact element of the REF 2014 submission process worked for HEIs and research users will be important for future rounds of assessment. [For "Preparing Impact Submissions for REF 2014: An Evaluation. Approach and Evidence," see ED561159; for "Preparing Impact Submissions for REF 2014: An Evaluation. Findings and Observations," see ED561162; for "Assessing Impact Submissions for REF 2014: An Evaluation," see ED561165.]