How long a Nigerian business should keep its records
How far back the NRS can raise an additional assessment, the matching window for refund claims, and what a Nigerian business keeps behind each return.
By Achekam · · 4 min read · For Running a business businesses in Nigeria
Records cut both ways. Most owners think of them as defence: the papers you need when the tax authority comes asking. In Nigeria they are also how you get money back. The same time limit that bounds how far back the NRS can reach also bounds how far back you can claim a refund of tax you overpaid, and a claim without documents behind it is only a hope.
So the question "how long do we keep this?" has two answers that point the same way. This article explains the two six-year windows at the time of writing, what the research behind it does not settle, how the new Rev360 portal fits in, and a practical list of what to keep behind each kind of return.
Six years for additional assessments
The NRS can raise additional assessments within 6 years. If, during that period, the NRS decides that a return understated the tax due, it can assess the difference. Your defence is the evidence behind each figure in the return: invoices, contracts, bank statements, computations.
A year still inside the window is a year you may have to explain. Once a year falls outside it, an additional assessment for that year is out of time on the face of the rule; ask your adviser whether any exception could reach further back. Either way, the window is the minimum span your records should cover.
Six years to claim a refund
A refund must be claimed within 6 years. If you discover that you paid too much, perhaps a payment made twice, or tax paid on income later found not to be taxable, you have the same six years to claim it back. The claim will need documents: the original invoice, the credit note, the withholding tax evidence, the payment receipt.
Throwing out records early can cost you a refund as surely as it can leave an assessment unanswered.
No general retention period in the research
The research behind this article does not state a general record-keeping period for Nigeria. The six-year windows tell you how far back the NRS and you can go on assessments and refunds. They are not, by themselves, a rule that every document must be kept for exactly six years.
The Nigeria Tax Administration Act 2025 sets out the duty to keep records, and the NRS's plain summary of the Act covers the duties to register, file and pay on time, keep records, the NRS's audit and investigation powers, penalties and the right to appeal. Read it with your adviser, and ask whether any other rule you are subject to, from company law to your industry regulator, sets a longer period.
Rev360 keeps the filing history, not your evidence
The NRS launched Rev360 on 30 April 2026 to replace TaxPro Max, and TaxPro Max profiles, history and balances were migrated automatically. That means the portal holds a record of what you filed and paid.
It does not hold your evidence. The portal knows the VAT figure you declared; it does not hold the invoices that add up to it, the contracts behind your income, or the workings behind a deduction. The supporting documents are yours to keep, and they are what an assessment or a refund claim will turn on.
Till records kept for seven years in Achekam
If you use Achekam's till, your till records are kept for 7 years. That is South Africa's retention period: no Nigerian retention period was researched, so Achekam applies the South African one to Nigerian till records until Nigerian and Kenyan retention policies exist. For your till history, that comfortably covers both six-year windows.
Source documents stored with fingerprints
For the rest, Achekam's Document Centre is a folder-based store where you upload files or whole folders and then preview, download, rename, move, tag, archive and search them. A new version of a file keeps the earlier ones. Uploads go in batches of up to 25 files, at up to 100 MB per file by default.
Every stored file gets a SHA-256 fingerprint calculated from its contents, so you can later show that a document is the one you stored and has not been altered. Executable files are refused by default, and every upload passes a malware check (ClamAV where the server is configured for it, otherwise a built-in check).
What to keep behind each return
| Return | Keep behind it |
|---|---|
| Monthly VAT return | Sales invoices and credit notes with their e-invoicing references, purchase invoices, the return as filed, the payment receipt |
| Withholding tax | The payee's invoice, your calculation, the remittance receipt, any certificate issued |
| Annual company return | The financial statements, tax and capital allowance computations, the return as filed, proof of payment |
| Payroll | Approved pay runs, the schedules per State and fund, filing references and payment receipts |
| Refund claims | Everything that shows the overpayment, and the claim as submitted |
A practical routine once each year's annual return is filed: make a folder for the year in Document Centre, upload anything still on paper, add the statements and the returns, tag the long-life records such as asset invoices and leases, and note on your calendar the year in which the six-year windows close. If a year is under objection or appeal, hold its records until the matter ends; the dates are in objecting to a tax assessment in Nigeria or Kenya.
Good records also make the next tax clearance certificate easier to obtain; see getting a Nigerian tax clearance certificate.
General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.
