The COVID-19 pandemic has caused a significant deterioration in public finances, adding to pre-existing strains from long-term structural challenges including population ageing, climate change, rising inequality, digitalisation and automation. This report, originally prepared for G20 Finance Ministers and Central Bank Governors at the request of the Italian G20 Presidency, considers the challenges and opportunities of developing public fiscal policy strategies as countries seek to “build back better”. The report focuses in particular on how tax policy can be designed comprehensively so that fiscal systems can deliver a balance of equity, growth and sustainability, highlighting some of the key considerations that policymakers should take into account to ensure optimal tax policy design and the successful implementation of tax reform.