Socio-economic circumstances influence later-life employment participation, which may take different forms as retirement processes are complex. We aimed to explore the diverse effects of various socio-economic sub-domains on pre- and post-retirement employment. We used Finnish register data to examine socio-economic predictors of time to retirement (i.e. receiving the statutory pension) using Cox regression analysis and on time spent in post-retirement employment using repeated negative binomial regression analysis over a follow-up between the ages of 63 and 68, i.e. the flexible pension age range. An average wage earner still employed at age 62 spent 13.5 months in pre-retirement employment (this corresponds to time to retirement) and 4.8 months in post-retirement employment. Those with tertiary education retired later, but the educational differences in the total time spent in employment were small when post-retirement employment was also considered. There was little variation in the timing of retirement by household income, but those in the highest quintile spent the longest time in post-retirement employment. Upper non-manual employees, home renters and those with high household debt retired later, and those with high household debt also spent a longer time in post-retirement employment. In a national flexible pension age system, high occupational class and household income thus appear to encourage either later retirement or participation in post-retirement employment. However, economic constraints also appear to necessitate continued employment.