Purpose The purpose of this study is to examine the impact of the 2020 COVID-19 lockdown on the audit fees and audit delay of audit client firms located in 52 countries and audit firm offices located in 40 countries. Design/methodology/approach Using archival audit data from Audit Analytics in the fiscal year 2020, this study examines the impact of the length of COVID-19 lockdown and other public health restrictions, measured by the stringency index (Hale et al., 2021), on audit fees and audit delay using a multivariate regression analysis. Findings Based on a sample of 2,726 US firms and 718 non-US firms from 51 different countries outside the USA and audit firm offices in 40 countries during the fiscal year 2020, the authors find that the COVID-19 lockdown and public health restrictions increase audit fees and audit delay. However, non-US firms experience longer audit delay because of the lockdown than their US counterparts. In addition, longer lockdown and greater restrictions increase the audit fees and audit delay of non-US firms with high audit risk at a greater rate than those of US firms with high audit risk. Practical implications The results of this study suggest that auditors increase audit fees and have longer audit delay when facing more COVID-19 restrictions. Increased audit fees and audit delay are likely to result from higher perceived audit risk and, consequently, additional audit effort to design new procedures, train staff to use the new procedures and implement them amid the pandemic restrictions. The impact of COVID lockdown and restrictions on audit fees and audit delay are more pronounced for non-US firms with greater audit risk. The results of this study suggest that audit firms should quickly adapt to the evolving audit, risk and financial landscape created by the pandemic. Originality/value Using archival audit data and large sample size, this study provides the first empirical evidence of the impact of lockdown and public health restrictions during the first wave of COVID-19 outbreak on audit processes as measured with audit fees and audit delay.