how many illegal immigrants in uk 2025

Direct answer: Estimates of unauthorized or “illegal” immigration in the UK are uncertain and vary by method. Recent public estimates place the unauthorised migrant population in the hundreds of thousands, but all figures have large margins of error and are sensitive to how groups are defined (including asylum seekers, UK-born children, and indefinite leave to remain). For context, some recent studies reported central estimates around the mid-to- high hundreds of thousands, with ranges often cited from about 700,000 up to roughly 1 million depending on the assumptions used. However, more recent assessments have revised or contextualized these numbers, and official statistics emphasize the difficulty of counting people who do not wish to be found. If you’d like, I can pull the latest publicly available figures from migration research sources and official statistics to give you a clearer, up- to-date range and explain the key definitional differences driving the numbers.