A high level of school absence has persisted across many countries since the COVID-19 pandemic. We use English data to investigate whether a student's absence during the pandemic had a causal impact on school attendance and academic progress in future years, using variation in local regulations during the pandemic (not aimed at schools). We find that more stringent regulations caused higher rates of school absence at that time, leading to lower attendance and rates of achievement in subsequent years. Our evidence suggests that the persistent effect is caused by changes in parents' and pupils' attitudes to attendance and not because of rules forcing students to stay at home when they had been in contact with others who had COVID-19. The effects of policy restrictions on contemporaneous and persistent absences was stronger for lower socio-economic groups.