This paper investigates bunching at personal tax thresholds in the UK over a 40-year period. At kinks, where the marginal tax rate rises, it finds bunching among company owner-managers and the self-employed, but not those with only employment income. Notches, where the average rate rises, provide compelling evidence that this is because most employees face substantial frictions: fewer than a quarter bunch even where doing so would increase consumption and leisure. This new approach identifies selection for decomposing responses into hours and wage components. This paper finds that employees who bunch at notches are higher-hours, lower-wage, part-time workers.