Nigeria Tax Administration Act, 2025 · s.34–s.36
Self-assessment, and what the authority can do with it
Your return is your assessment — but the authority can accept it, add to it, or replace it with its own judgement.
Who this lands on: Every taxable person.
Filing a return in the prescribed form is itself an assessment of the tax payable, including a nil or negative amount. An electronic return counts even when the form pre-fills figures for you.
The tax authority may accept it as it is, accept it and raise an additional assessment, or reject it and assess to the best of its judgement.
Where you did not declare the true amount, the outstanding tax runs from the original due date — not from the day they noticed.
An administrative assessment (s.35) is what you get when no return arrives. Filing something honest and complete is always better than filing nothing.