Governments rely on citizen compliance for official rules to be effective. Yet achieving compliance is often tricky, particular when individual costs are high. Under what conditions will citizens voluntarily respect collective rules? We explore public compliance with SARS-CoV-2 (coronavirus) restrictions, focusing on the role of political trust. We anticipate that the effects of trust on compliance will be conditional on the presence of other factors, notably fear of infection. Low levels of fear may provide room for trust to shape compliance; yet high levels of fear may ‘crowd out’ the role of trust. We hypothesize that, at the pandemic’s outset, compliance was likely to be shaped more by fear than by trust. Yet as the pandemic progressed, the impact of fear on compliance was likely to have weakened, and the impact of trust to have strengthened. These hypotheses are tested using longitudinal data from Austria, Germany, and the United Kingdom.