Serco Group is a British outsourcer of public services ranging from facilities management to systems engineering. It serves governments and corporations across five sectors: Defense, Justice & Immigration, Transport, Health, and Citizen Services. It operates in more than 20 countries and organizes its business by geographic region with segments devoted to the UK & Europe, North America, Asia/Pacific, and the Middle East. The company generate most of its revenue from United Kingdom and Europe. The company has designed and operated intelligent transport networks, handled immigration from point-of-entry to repatriation, and securely detained and rehabilitated prisoners, among other activities. Serco traces its roots to 1929, and was listed on the London Stock Exchange in 1988. In 2019, Serco acquired Naval Security Business Unit (NSBU).