There is a move towards online data collection in the UK, including the plan to collect 75% of responses online in the 2021 Census. Online survey response is complicated by respondents using different devices. So far, no research has been conducted in the UK to study characteristics of people using different devices in mixed-device online surveys. This analysis uses all publicly available UK social surveys with an online component: Understanding Society Innovation Panel, Community Life Survey, European Social Survey, 1958 National Child Development Study, and the Second Longitudinal Study of Young People in England. Bivariate analysis and logistic regressions are used to study significant correlates of device use in online surveys. The results of bivariate analysis suggest that age, gender, marital status, employment status, religion, household size, children in household, household income, number of cars, and frequency of internet use are significantly associated with device used across surveys. The associations with age, gender, employment status, household size and education are consistent with the findings from other countries. The knowledge about characteristics of respondents using different devices in online surveys in the UK will help to understand better the response process in online surveys and to target certain subgroups more effectively.