Tax Audit Outcomes and Revenue Recovery in Nigeria’s Large Taxpayer Office

This research examines tax audit outcomes and their contribution to revenue recovery within the FIRS Large Taxpayer Office (LTO), which administers the tax affairs of Nigeria's largest corporate taxpayers. The LTO plays a critical role in the federal revenue system, with its audit and enforcement activities generating substantial additional assessments each year. However, the efficiency and fairness of LTO audit processes have attracted controversy, particularly regarding the frequency of post-audit disputes escalated to the Tax Appeal Tribunal. Using a professional PGD research design, the study analyses LTO audit outcome data from four recent fiscal years, categorising assessments by sector, size, and resolution pathway. Interviews with ten tax directors from companies audited by the LTO and five senior LTO audit managers provide qualitative depth. Thematic analysis and descriptive revenue trend analysis are employed. The study expects to find that sectoral audit coverage is uneven, with financial services and oil companies receiving disproportionate audit attention relative to their actual risk profile, while under-audited sectors such as professional services and technology exhibit higher under-reporting rates. Recommendations include implementing a structured risk-based audit selection matrix at the LTO, publishing sector-specific audit guidance to reduce ambiguity, establishing a formal pre-filing resolution programme to address contentious tax positions before formal assessments, and improving the speed and consistency of dispute resolution for LTO-generated assessments. Keywords: tax audit, Large Taxpayer Office, revenue recovery, FIRS, corporate taxation.