This paper documents a positive correlation within European labour markets between the proportion of full-time employees with earnings on the minimum wage and the extent of underreporting of earnings in the economy. Using a simple model of a competitive labour market, I show how this correlation can emerge as a result of the common dependence of both quantities on the strength of enforcement of fiscal regulation. This suggests that a high spike in the wage distribution at the minimum wage level is, in some contexts, an issue of fiscal enforcement, more than a labour market issue.