PurposeSmart device use for work during family time is a growing issue of concern and is likely exacerbated by the COVID-19 pandemic. The authors test a broad range of well-being outcomes (job anxiety, job depression and insomnia) to extend the literature. Work–family conflict was included as a mediator with age as a moderator.Design/methodology/approachThe study uses representative data from 422 New Zealand employees across a wide range of occupations, sectors, and industries from late 2020. Confirmatory factor analysis (CFA) of the data was used and moderated mediation analysis was conducted.FindingsOverall, hypotheses were supported, with mWork positively influencing work–family and family–work conflict, and all well-being outcomes. Work–family and family–work conflict acted as mediators and age interacted with mWork leading to more conflict for older workers. Finally, moderated mediation effects were supported with age acting as a boundary condition, whereby the indirect effect of mWork on well-being outcomes increases as age increases.Research limitations/implicationsThe findings highlight the danger of using mobile devices to work in family time and highlight the additional risks for older workers.Originality/valueThe mWork literature has a limited focus on well-being outcomes, and the New Zealand data provides insights from a largely underrepresented population in the literature. Further, the use of age as a moderator of mWork towards well-being outcomes provides further originality.