Corporate Income Tax and Profitability of Quoted Companies on the Nigerian Exchange Group

This study investigates the relationship between corporate income tax obligations and the profitability of companies listed on the Nigerian Exchange Group. Corporate income tax represents a significant financial obligation that directly affects after-tax earnings, retained profits, and shareholder value. Despite its centrality in corporate finance, empirical studies linking tax expense management to firm-level profitability within the Nigerian capital market remain relatively sparse at the undergraduate research level. The study adopts an ex-post facto research design, analysing audited financial statements of 30 listed companies drawn from the consumer goods and industrial sectors over a five-year period. Data on tax expense, profit before tax, and profit after tax are extracted and analysed using correlation and simple linear regression techniques. The study expects to find a significant negative relationship between effective tax rates and net profit margins, particularly among firms with limited access to tax planning advisory services. It also explores whether companies in tax-incentivised sectors record comparatively higher post-tax profitability. Recommendations include encouraging firms to adopt legitimate tax planning strategies, engaging qualified tax consultants, and advocating for legislative clarity on capital allowance computations to reduce disputes with the Federal Inland Revenue Service. This research provides a foundational understanding of tax-firm performance dynamics for undergraduate students of taxation and accounting. Keywords: corporate income tax, profitability, Nigerian Exchange Group, effective tax rate, financial performance.