Here’s a clear, practical guide to filing your personal income tax in Oyo State Internal Revenue Service (Oyo State, Nigeria) — including deadlines, responsibilities, and step‑by‑step instructions so that you can do it correctly and avoid mistakes.

📅 1. Tax Filing Deadlines You Must Know

🧾 A. Employer Filing (PAYE Returns)

If you are an employer, the annual return showing all salaries and tax deducted **must be filed by **🗓 January 31 each year for the preceding year’s income. This is backed by the Personal Income Tax Act and current Oyo revenue practical

📑 B. Individual Self‑Employed or Direct Assessment

For self‑employed individuals (Direct Assessment) or individuals responsible for their own filing, many states — including Oyo — follow the federal filing window, which is generally within 90 days after the end of the fiscal year (December 31) — i.e., by March 31. This aligns with national practice and similar state guidance

👉 For most people in Oyo State, the practical deadline for filing personal income tax returns is March 31 each year. (This is confirmed across states with similar rules, and Oyo State has enforced the same pattern in previous years. )

🧠 2. Who Must File Personal Income Tax?

You must file if you are:

An employee earning a salary/wage and resident in Oyo State. Your employer usually handles tax deduction and remittance but you still must ensure the declaration process is done.

Self‑employed (e.g., trader, consultant, freelancer, small business owner).

A casual worker, temporary contract worker, or anyone earning taxable income.

IMPORTANT: Tax applies to all income — salary, business profits, allowances — after allowable reliefs and exemptions.

🧾 3. How to File (Step‑by‑Step)

✔️ A. If You Are Employed (PAYE)

At the start of the year, file your Annual Income Declaration with OYIRS (your nearest tax office).

After assessment, you will get an Annual Tax Estimate showing your taxable income and deductions.

Give the estimate to your employer. Your employer then deducts PAYE each month and remits it to the Internal Revenue Service by the 10th of the following month — e.g., January tax by February 10.

Your employer should file the Annual Return by January 31.

Tip: Confirm with your employer that they have filed the annual returns and remitted the tax on your behalf.

✔️ B. If You Are Self‑Employed (Direct Assessment)

Register with OYIRS and obtain a Tax Identification Number (TIN) if you haven’t already.

Complete your Annual Tax Return form with details of your income and allowable deductions.

Submit the return at your nearest OYIRS office or via the OYIRS Self‑Service portal.

You will receive an Assessment Notice stating how much you owe.

Pay the assessed tax through approved banks or online channels, then collect your Revenue Receipt

Keep all supporting documents (bank statements, receipts, invoices) in case of review.

👉 Use the OYIRS Self‑Service portal to generate payment codes, check payment status, and even access your tax profile online.

❌ 4. Common Filing Mistakes to Avoid

Mistake

How to Avoid

Missing the deadline

Note the deadlines (Jan 31 for employers; March 31 for Direct Assessment)

Incorrect income figures

Add all income sources: salary, side gigs, business profits

Forgetting deductions

Include lawful reliefs like pension, NPF, NHF

No TIN or incomplete registration

Register early with OYIRS

💡 5. Additional Tips

‑ Keep Records: Maintain clear proof of income, expenses, and payments.

‑ Confirm Remittances: If employed, check that your employer actually remits monthly PAYE.

‑ Get Help: If this is your first time, consider going directly to your nearest OYIRS office for guided assistance.

📌 Summary:

🗓 Employers file by January 31 (annual return).

🗓 Individuals (Direct Assessment) usually file by March 31 for the previous year with OYIRS.

Online options exist through OYIRS self‑service, but office support can help reduce errors.

Accurate income logs and correct TIN registration are essential.

If you want, I can provide specific forms and downloadable links for the Oyo State tax filing process or walk you through completing each section of the return step‑by‑step.