This paper addresses an identified gap in knowledge about whether, and how, perceptions of corruption may influence personal income taxpayer compliance behaviour. It examines how perceptions of five forms of corruption may impact upon intentional tax underreporting behaviour by adopting a sequential mixed-methods approach. Initially, a qualitative phase was carried out by conducting semi-structured in-depth interviews with nine participants (three taxpayers, three tax agents and three tax officers). The secondand corephase of the research involved extensive data collection using a mixed-modes field survey conducted through 12 tax offices across four Indonesian regions. A total of 397 respondents were surveyed, comprising 196 self-employed and 201 employed taxpayers. Three principal findings have emerged from the data. First, as expected, the data from both the qualitative and quantitative phases suggest that high levels of perceived corruption were evident in Indonesia. Second, the quantitative findings clearly demonstrate that perceptions of corruption undermine taxpayers’ intention to report actual income. Third, the findings ultimately suggest that high levels of perceived general corruption (that is, abuse of entrusted power by public officials for private gain), grand corruption (that is, corruption involving high-level public officials) and grand tax-corruption (that is, corruption involving high-level tax officials) were influential on intentional tax underreporting behaviour. The present empirical results support the notions that perceptions of corruption are important determinants and have a negative impact upon tax compliance behaviour. The results also imply that combating corruption, especially grand corruption, would have a beneficial effect on voluntary tax compliance in Indonesia.