Good records are your starting position, long before any letter arrives. What happens once one does follows a fairly fixed sequence.
Why records come first
At least six years after the year of assessment is the minimum period the law expects you to keep your books for. A company that cannot produce them when asked faces ₦50,000.
Our piece on how long to keep tax records covers this duty in full. It is worth reading before a query arrives, not after.
What a notice of assessment sets in motion
A notice of assessment from the Nigeria Revenue Service (NRS), formerly FIRS, starts two separate clocks at once. One is for objecting. The other is for paying.
The 30-day window to object
You have 30 days from receiving the notice of assessment to object in writing. The objection has to do real work. It must set out exactly what you dispute, the change you are asking for, your reasons, and the income and tax you do accept.
A one-line objection that just says the figure looks wrong is unlikely to meet that standard.
The separate window to pay
30 days from receiving the notice is the deadline to pay, running alongside the objection window rather than after it. Objecting does not automatically pause this deadline on its own.
Ask an adviser how to handle an assessment you intend to dispute while this payment deadline is still running. Getting both wrong at once is a costly mistake.
The penalty for blocking access
A separate, steeper penalty exists for a different kind of problem: blocking the NRS's access to your systems or records after being asked. ₦1,000,000 for the first day and ₦10,000 for each further day, once 30 days pass from the notice.
This is not part of the ordinary assessment process. It is aimed specifically at obstruction, and it is worth knowing about even if you never expect to be in that position.
What happens if both windows pass unused
Missing the objection window generally means the assessment stands as issued. Missing the payment window brings the late-payment penalty and interest that apply to any unpaid tax.
Treat both dates as real deadlines from day one, not as figures to revisit once the situation feels more urgent.
Common mistakes
- Waiting for the objection to work itself out before paying anything. The payment deadline runs on its own timeline.
- Filing a vague objection. The law expects specific disputed items, reasons and figures.
- Having no records ready when the notice arrives. By then, it is too late to build the habit the law expects from the start.
For the record-keeping duty behind all of this, read how long to keep tax records. Once your filings are current, a tax clearance certificate becomes something you can request. Start a request once you need one, and browse the NRS and Rev360 hub for more.