The Department relies upon a disturbingly weak evidence base to assess the impact of its immigration enforcement activity. The lack of reliable evidence on what works prevents it from planning and prioritising its activities effectively. The Department accepts that it cannot easily use data to measure the impact of the £400 million it spends each year in Immigration Enforcement and has a “dearth of information” in some aspects of its activities. It allocates resources between its different immigration responsibilities based on “judgements”, but if those judgements are not based on evidence, it is unclear what factors the Department is considering. Worryingly, the Department could not always provide evidence or data to support its decisions, for example on its strategy to tackle organised immigration crime, or to demonstrate understanding of the problems it faces, for example the impact of accessible and good quality legal advice on its success in returns. Although it is working to increase its analytical capabilities to learn from the challenges it faces, this work is only at an early stage. Recommendation: Within six months of this report, the Department should put in place a detailed improvement plan for its collection, use, and analysis of data. It should write to the Committee and set out: • The skills gaps it has identified in its analytical capability and how it intends to fill them; 6 Immigration enforcement • A plan for transforming Immigration Enforcement into a data-led organisation, including timescales and priorities for improvements; and • How it intends to use this in the future to help plan and prioritise its activities.