The International Organization for Migration's (IOM) Displacement Tracking Matrix (DTM) in partnership with the World Food Programme (WFP) conducted a biometric registration exercise in Akobo East County, Jonglei and Ulang County,Upper Nile between September 2019 and February 2020 covering four locations in Akobo East (Bilkey, Dengjok, Gakdong, and Nyandit) and one location in Ulang (Wanding). These locations near the Sobat River were primarily accessed via boat. The exercise had to be paused temporarily due to insecurity but resumed soon thereafter.DTM registered a total of 43,783 individuals (8,839 households) in both counties with 41,644 individuals (8,390 households) registered in Akobo East County and 2,139 individuals (449 households) in Ulang County. Bilkey was home to the highest population with 27,375 registered individuals accounting for 65.7 per cent of the population in Akobo East County. Some 13 per cent of registered individuals were categorized as having one or more vulnerabilities including visual impairments, other physical disadvantages, single parent headed households and serious medical conditions. Mobile teams enabled DTM to reach populations that were otherwise unable to reach registration sites due to physical impairments or due to insecurity