We study the taxation of the minimum wage in an environment with imperfect enforcement and informality. We leverage an increase in the audit threat for earnings below a reporting threshold at twice the minimum wage in Hungary and estimate reporting and employment responses with administrative panel data. Using bunching estimators and difference-in-differences methods, we show that a substantial share of those who report earning the minimum wage earn at least the same amount off the books. When enforcement is imperfect, a taxed minimum wage serves as a backstop on underreporting and recovers some revenue but also increases informality.