Nigerian company self-assessment returns
When a Nigerian company, small ones included, must file its annual self-assessment return, which accounts go with it, and how a firm prepares it.
By Achekam · · 4 min read · For Accountants & audit firms in Nigeria
A common assumption among small Nigerian business owners is that a company paying no company income tax has nothing to file. Under the Nigeria Tax Act regime that took effect on 1 January 2026, a small company does indeed pay 0% company income tax. It still files a return every year.
For a firm, that means the filing season includes every company client, not just the ones with tax to pay. This article covers who must file, when, which accounts go with the return, and how a firm can run preparation, review and approval before someone files it on Rev360.
Every company files, small ones included
Every Nigerian company, including a small or exempt one, must file an annual self-assessment return. From 1 January 2026, a small company pays 0% company income tax and every other company pays 30%, but the obligation to file does not depend on the rate.
Treat the return as the evidence of the company's position. A small company that does not file loses the chance to show, on the record, that it qualified for the 0% rate, and exposes itself to penalties for a late return. Penalties for late Nigerian returns and payments sets out what that costs.
Six months after year end
For a company that has been in business for more than 18 months, the return is due within 6 months after its year end, and the tax is paid by the filing due date.
| Year end | Return and tax due by |
|---|---|
| 31 December 2026 | 30 June 2027 |
| 31 March 2027 | 30 September 2027 |
| 30 June 2027 | 31 December 2027 |
A company in its first 18 months follows a different first-return rule. The NRS page on company income tax sets out the deadlines, including the one for a new company, and what the return must contain: audited or taxpayer-attested accounts, tax and capital allowance computations, proof of payment and the effective-tax-rate computation.
Because tax is paid by the filing date, the return cannot be left to the last week. The tax must be computed, approved and paid in time as well.
Audited or taxpayer-attested accounts
The return goes with the company's accounts. A small company may attach taxpayer-attested accounts instead of audited ones; other companies attach audited accounts.
Two practical consequences for the firm:
- For audit clients, the audit timetable now drives the tax deadline. An audit signed in the last week leaves no time to prepare, review and approve the return. Plan the audit to finish well before the six-month date.
- For small companies, someone at the company attests the accounts. Make sure the client understands what they are attesting to, and that the accounts the firm prepares are ready in time for that attestation.
Which companies count as small is not straightforward in 2026. Two official texts of the 2025 tax Acts disagree on the small-company turnover figure, and Achekam does not use that figure until one platform administrator chooses a candidate with a reason and a different administrator approves it. Until then the size class shows as undetermined, with what each candidate would give. Where a client sits between the candidates, the partner decides the position and records why.
Prepare, review and approve
Staff can open a Nigerian tax profile for a client in Achekam's Revenue Service Centre and start a return that moves through prepare, review and approve by different people. A return is prepared by one person, reviewed by a second and approved by a third, after which its rule snapshot and figures are frozen. An amendment later is a new version; nothing is overwritten.
Three conditions apply to the figures:
- Every Nigerian tax figure in Achekam's rule book was seeded "under review", and Achekam computes nothing from a figure until an Achekam platform administrator approves it. Check whether the rules are approved in your workspace.
- Achekam holds no Nigerian tax rule for periods before 1 January 2026 and refuses to compute them. A year that began before that date is outside it.
- A client's sales and purchase lines are typed in, because the client's own books are not linked.
Once approved, a reviewer can send the return to the client for e-signature with a summary PDF, and the signature is recorded as the client's approval. The summary never includes the working papers. A signed client approval before filing protects the firm if the client later disputes a figure.
Filing on Rev360
Achekam does not file Nigerian tax returns. A person with the firm's NRS filing permission files on Rev360 and uploads the receipt, and a different person verifies it before the return counts as filed. The NRS launched Rev360 on 30 April 2026 to replace TaxPro Max, rolling it out in phases.
No role receives the filing permission by default; a firm grants it to named people only. The research behind these articles found no screen that grants it, so recording a filing may be unreachable. Test it before the season. If it cannot be granted, keep the Rev360 receipt on the client's file with a note of who filed and when. How advisers work on clients' Rev360 profiles is covered in working on clients' Rev360 profiles safely.
The rates and the levy that sit inside the return are explained in Nigerian company income tax from 2026.
A season plan
List every company client with its year end and the date six months later. Mark which need audited accounts and which may attest their own. Work backwards from each due date to set the audit or accounts deadline, the tax computation, the client's e-signed approval and payment, and leave a margin for Rev360 itself.
General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.
