Financial Record-Keeping for Nigerian Businesses: What to Keep and for How Long

Records are the difference between answering a tax query in an afternoon and paying an estimated assessment you can't disprove. Nigerian law sets a floor for how long you keep them, data protection law sets a ceiling for some of them, and good practice fills the space in between. This guide covers all three.

The tax floor: six years

Section 31 of the Nigeria Tax Administration Act 2025 requires every person to keep books or records of account, even if no tax is due. Those records must be kept for not less than six years after the year of assessment to which the income relates (Official Gazette; Tax Appeal Tribunal copy).

Read the wording carefully. The clock runs from the year of assessment, not the date of the document. An invoice raised in March 2026 relates to 2026 income, so its six years run from the end of that year of assessment. In practice, that means into 2032 at least.

The six years aren't arbitrary. Section 36 of the same Act lets the tax authority raise an additional assessment within six years of an assessment. An audit started inside that window can carry on after it closes. Under the old laws, commentary noted that the time limit fell away in cases of fraud, wilful default or neglect (BusinessDay). We didn't find the equivalent wording in the 2025 Act, so ask your adviser before you rely on it either way.

What counts as a record

"Books or records of account" is broad. For a typical services business, this is the minimum set:

A payment voucher without its approval is half a record. If the auditor asks "who authorised the ₦2,750,000 Garki rent?", the answer should be in the file, not in someone's memory. Our guide to audit trails explains why.

Payroll and staff records

Payroll sits under two rules at once:

• Tax and pension law. Payroll is part of your books, so the six-year floor applies to pay runs, PAYE schedules and remittance evidence.
• Employment law. Commentary on the Labour Act notes that records of wages and conditions of employment must be kept for three years after the time they refer to (Mondaq). That's shorter than six, so the tax floor governs payroll figures.

The practical answer is to keep payroll financial records for at least six years after the year of assessment. Staff files that aren't needed for tax, such as old leave forms or job applications, may need to go sooner, which is where data protection comes in.

The data protection ceiling

The Nigeria Data Protection Act 2023 doesn't set a fixed retention period. It applies a storage limitation principle: keep personal data only as long as the purpose needs it (KPMG). A legal duty to keep a record, such as the tax floor, is a valid reason to keep it. Habit isn't.

So, for each kind of record that contains personal data:

1. Name the purpose and the rule, for example: "Payslips: tax records, six years after the year of assessment."
2. Set the retention period in a written schedule.
3. Archive former employees' data, restricted to the people who need it, rather than leaving it in day-to-day systems.
4. Delete or anonymise it when the period ends, and record that you did.

A retention schedule you can adopt

Confirm the schedule with your adviser. Then write it down, because a schedule nobody can find is no schedule at all.

Storing records so you can find them

• Digital first. Scan paper receipts on the day you receive them. A faded thermal receipt from Trans-Amadi won't survive six years in a drawer.
• One home per record type, not five shared folders.
• Name by period and number: 2026-10_INV-2026-0418.pdf sorts itself.
• Restrict access. Payroll and personal data are for the people who need them.
• Back up off-site, and test a restore once a year.

How Flux helps

Flux keeps invoices, receipts, statements, vouchers and pay runs together with the approvals and the audit log that sit behind them. Tax & Reporting exports VAT and WHT reports, payment and receipt exports, and audit coverage reporting, so the evidence for a period is a download rather than a search. The document archive in HR keeps staff documents in one place. Retention decisions remain yours; agree them with your adviser.