Why do firms engage in aggressive corporate tax planning and tax avoidance? (How) can self-regulation, through Corporate Social Responsibility (CSR), complement public regulation in minimising the negative impacts of aggressive corporate tax planning and tax avoidance on government tax revenues? These questions bring to the fore the tension between tax illegitimacy and legality, which can confuse actors – e.g. regulators, managers, tax accountants, lawyers, and consultants – and obfuscate tax policies (West, 2017). As such, the tension needs to be resolved to enhance tax compliance and minimise irresponsible strategic tax planning, which is an economic leakage. In addition, the questions seek to explore how the emerging field and practice of CSR in Nigeria, which has been predominantly and erroneously framed as philanthropy (Amaeshi et al., 2006; Amaeshi et al., 2015), can be leveraged, by interested actors, to address possible reductions in government tax revenues (partly as a result of aggressive strategic tax planning and tax avoidance schemes) by framing taxation as a responsible business practice. This dual mandate lies at the heart of this research project. Data collection will involve interviews and focus groups with selected tax actors. It is anticipated that the findings will contribute to practice, policy, and theory.