The Nigeria Tax Act and the Administration Act together

Which client questions a Nigerian firm answers from the Nigeria Tax Act and which from the Tax Administration Act, with a research routine.

By Achekam · 11 October 2026 · 4 min read · For Accountants & audit firms in Nigeria

A client asks two questions in one e-mail. Is the income from its new equipment-hire line taxable? And if it files the return a fortnight late, what will it cost? A junior opens the Nigeria Tax Act, searches for "late filing" and finds nothing useful. The answer is not missing; it is in the other Act.

Since 2026, Nigerian tax law has been organised around two statutes that work as a pair. Knowing which one answers which kind of question saves research time and prevents a familiar error: advising on half the law.

Substance in one Act, procedure in the other

The NRS describes the Nigeria Tax Act, 2025 as Nigeria's principal substantive tax law. It decides what is taxable and who is taxable. Procedures, enforcement and penalties sit in the Nigeria Tax Administration Act, 2025.

A rough rule of thumb follows:

Many questions need both. "Is this deduction allowed, and what happens if the NRS disagrees?" starts in the Tax Act and finishes in the Administration Act. Train staff to ask, at the end of every research note, whether the other Act has something to add.

Registration, records and information requests

The NRS's summary of the Tax Administration Act highlights the duties that apply to every taxpayer before any tax is computed. Under that Act, according to the NRS, all businesses and individuals subject to federal taxes must register with the NRS, and taxpayers must keep accurate records and provide information on request.

The NRS summary of the Nigeria Tax Administration Act sets out these duties in plain terms, together with the authority's audit and investigation powers and the right to appeal. It is a sensible page to send a client who asks why the firm needs so many documents.

For a firm, these duties shape client take-on and the year-end request list. A client that cannot produce records on request is exposed under the Administration Act, whatever the Tax Act says about its liability.

Penalties, interest and the right of appeal

The NRS says the Tax Administration Act sets out fines, interest and other consequences for late filing, late payment and underreporting, and gives taxpayers the right to appeal assessments and penalties. That is where the junior in the opening example should have looked.

The pairing works in the client's favour as well. A client facing a penalty it considers wrong finds its remedy in the same Act that imposed the penalty. When writing to a client about a penalty, cite both the provision that imposes it and the right to challenge it.

The laws repealed from 1 January 2026

The Nigeria Tax Act comes into effect on 1 January 2026 and from that date repeals, among others, the Capital Gains Tax Act, the Companies Income Tax Act, the Personal Income Tax Act, the Petroleum Profits Tax Act, the Stamp Duties Act and the Value Added Tax Act. The full list is in section 196 of the Act, and the NRS FAQ points readers to that section.

Two practical consequences:

• Old references must go. Engagement letters, checklists, templates and memos that cite the repealed Acts need updating for 2026 periods.
• Old law still matters for old periods. Audits, objections and appeals about years before 2026 may still turn on the repealed Acts. Keep both sets of references, clearly labelled by period.

Periods that straddle 1 January 2026 raise their own questions, discussed in years that straddle 1 January 2026. Differences between published copies of the Acts are covered in the two texts of the tax Acts.

The rule book behind Achekam's computations

Firms using Achekam should know how its computations relate to the two Acts. Every Nigerian and Kenyan tax figure in Achekam's rule book was seeded as "under review", and Achekam computes nothing from a figure until an Achekam platform administrator approves it. No firm user can change a rate.

A firm's partners and administrators can read the approved statutory rules Achekam's decisions use in the Regulatory Rule Book, with their change log. Only Achekam's platform administrators change those rules, and never one person alone. When a computation surprises a reviewer, the rule book is the place to see which rule produced it, and the Act is the place to check whether the rule matches the law.

There is also a firm boundary on time. Achekam holds no Nigerian tax rule for periods before 1 January 2026 and refuses to compute those periods. Because company tax and levy rules resolve on the first day of the period, a period that straddles 1 January 2026 is refused as well. Work on those periods belongs in the firm's own papers, under the law that applied.

A research routine for client questions

A simple routine keeps research consistent across the team:

1. Classify the question. Substance, procedure or both.
2. Check the period. Is it governed by the 2025 Acts, the repealed laws, or does it straddle 1 January 2026?
3. Read the primary text. The relevant section of the Act, not only a summary.
4. Check NRS guidance. Any guideline or circular that interprets the section.
5. Check the other Act. What does it add on registration, records, deadlines, penalties or appeals?
6. Record the answer. Cite sections from both Acts where both apply, and note the date of the research.

Pick three recent research notes from the tax team and test them against the routine. Where a note answers a substance question without the procedural consequence, or the reverse, add the missing half and use the example in the next team meeting.

General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.