This chapter is about the mandatory disclosure of income tax as required by international financial reporting standards (IFRS) and standards issued by Portuguese regulatory bodies. The chapter also elaborates the most relevant disclosures from the perspective of corporate social responsibility (CSR). Furthermore, it highlights the most influential CSR reporting standards to answer the question that whether these standards adequately address the issue of income tax payment as a factor of CSR. Finally, it also reviews the international and Portuguese theoretical and empirical academic research available about income taxes and related subjects, such as disclosures, corporate tax as a CSR matter, and tax aggressiveness of corporations. Future research may be conducted geographical reporting of income tax expense and its relationship with the effective tax rate (ETR) and other independent variables.

Purpose -The purpose of the study was to evaluate reporting for income tax from a social responsibility perspective. Specifically, the research aims to ascertain the relationship between various aspects of income tax disclosure, namely its extent, effective tax rate and reporting for tax in corporate social responsibility reports, and various factors such as size, profitability, leverage and sector.Design/methodology/approach -Data collected from financial and corporate social responsibility reports covering the 2010-2014 period of entities included in the Portuguese Stock Index (PSI) 20 were used to build two indices. Using the logistic regression technique to assess the data gathered for two models, the indices were used as the dependent variables within the first model, and the effective tax rate was used in the second one. Size, profitability, leverage, sector and the effective tax rate were chosen as independent variables.Findings -The findings demonstrate the existence of a relationship between disclosure indices and size (positive), leverage (negative) and sector (negative). For the effective tax rate, only sector revealed a significant positive relationship.Originality/value -The study contributes to the relatively novel idea of viewing income taxes as a matter of corporate social responsibility, by focussing on reporting. To the best of the authors' knowledge, the study is unique in analysing the data collected from the corporate social responsibility perspective.