Linking survey and social media data has gained popularity. However, obtaining consent from respondents to link social media is a known challenge. Using data from a nationally representative survey of the U.K. this study investigated whether respondents' a) activity frequency, b) activity variety and c) technical skills with smartphones are associated with consent to link Twitter data to survey responses. Additionally, this study explored mediating role of privacy and security concern and moderating effects of age, gender, employment and educational level to better understand the influences of privacy concern on Twitter linkage consent. Results showed that activity variety with smartphones is positively associated with Twitter linkage consent, and privacy concern mediated the effects of activity frequency and activity variety with smartphones on linkage consent. Age and employment status moderated the associations between privacy concern and linkage consent, with younger and employed respondents being more likely to be affected by privacy concern.