The share of overtime hours within total hours worked in Britain has declined from 4.8% to 2.9% between 1999 and 2018. This is equivalent to 321 thousand full-time jobs. We investigate this decline focussing on full-time and part-time males and females together with overtime pay effects that include the implications for the gender pay gap. We test for economic, structural and cyclical influences via a two-part regression model that allows us to differentiate between the incidence of overtime working and the average weekly hours of overtime workers. This investigation features collective bargaining coverage, job mobility, the minimum wage, industrial composition and the public/private sector dichotomy. The analysis covers the whole economy embracing nineteen 1-digit industries as well as a separate insight into the manufacturing industry where we feature vehicle manufacture.