Appraisal of Self-Assessment Tax Policy in Nigeria

Implementation of self-assessment policy is seen as enhancing tax revenue generation, reducing operational cost and operating in line with international best practices. This study was designed to appraise the self-assessment tax policy in Nigeria by exploring income streams from CIT, PPT, VAT against GDP (at current basic prices) and annual budgets from 2002 to 2019. The study applying Ordinary Least Square statistics revealed the tax streams impacted GDP both in the pre and post self-assessment periods though their impacts varied. The efficiency of the implementation of the self-assessment policy tested using tax to GDP ratio and tax to budget ratio revealed pre self-assessment period performing better than the post self-assessment period as pre self-assessment period tax to GDP ratio is 6.63 per cent as against post self-assessment period tax to GDP ratio of 4.23 per cent. Also, pre self-assessment period tax to budget ratio is 119.62 per cent as against post self-assessment period ratio of 92.18 per cent. This is attributable to decline in performance during the post self-assessment period as a result of reduction in petroleum profit taxes occasioned by decline in taxable profits of companies operating in the petroleum sub-sector due to slump in global crude oil prices. The study also found Nigeria’s tax to GDP ratio to be far below average in other regions and the lack of harmonization of tax revenues by States and the federal government for a realistic evaluation.