What Is an Acceptable Plagiarism Percentage in Nigerian Universities?
There is no single national percentage. The limit is set institution by institution, and Nigerian universities do not agree with one another. Covenant University’s postgraduate handbook states a maximum allowable limit of 20%. Obafemi Awolowo University’s January 2026 thesis guidelines set no numeric threshold at all, and require a signed anti-plagiarism declaration instead.
Why does everyone say 20%?
Because some institutions really do publish 20% — and that number then gets repeated as though it were a national rule handed down by the National Universities Commission. It is not.
Covenant University’s postgraduate students’ handbook is explicit. On submission of a PhD thesis it requires evidence that the candidate’s department has subjected the thesis to a plagiarism test, and states: “The maximum allowable limit for direct copying or lifting from other sources and/or unreferenced portions is 20%. Any percentage value above this threshold shall be rejected.” Elsewhere the same handbook states that a thesis “shall be rejected if it fails the ‘Plagiarism test’ (i.e. contain more than 20 % direct copying or lifting from other sources and/or unreferenced portions)”, that the test is carried out by the Centre for Learning Resources, and that “Plagiarism shall attract an immediate withdrawal of degree if discovered after it has been awarded.”
That is a real, published, enforceable threshold. It applies at Covenant University. It does not automatically apply to you.
What do other Nigerian universities say?
We opened the current published guidelines from two more institutions. They are strikingly different.
| Institution | Document | Numeric threshold | What it requires instead |
|---|---|---|---|
| Covenant University | Postgraduate students’ handbook | 20% maximum | Departmental plagiarism test, evidence submitted to the School of Postgraduate Studies |
| Obafemi Awolowo University, Ile-Ife | Postgraduate College, Guidelines for Writing Theses for Higher Degrees, January 2026 | None stated | A signed anti-plagiarism declaration bound into the thesis as a preliminary page |
| University of Ibadan | Postgraduate College, Guidelines for Writing Theses and Dissertations and the University of Ibadan Manual of Style, revised edition 2023 | None stated | Full acknowledgement of all sources under its own house referencing style |
At OAU, the anti-plagiarism declaration is not a formality tucked into an appendix. It is item (b) in the prescribed order of preliminary pages, immediately after the title page, and it must be signed by the candidate. The prescribed wording has the candidate state that they “understand the interpretation of plagiarism” and are “well aware of the University’s policy in this regard”, and that the thesis is their own original work with other people’s work “properly acknowledged and referenced in accordance with University’s policy”.
Read what that shifts. Where there is no percentage, there is no score you can hide behind. You are signing a personal declaration, and the standard is honest attribution rather than a number.
Does the NUC set a national limit?
The National Universities Commission is the statutory regulator of Nigerian university education. Its published functions include laying down Minimum Academic Standards and accrediting degrees, and it publishes the Core Curriculum and Minimum Academic Standards across sixteen disciplines. In the materials the Commission makes publicly available, no single national similarity percentage is published for student work.
So when a website tells you “the NUC allows 20%”, ask where that is written. Institutional policy is where this actually lives.
Is a similarity score the same thing as plagiarism?
No, and this is the most expensive misunderstanding a final year student can carry into submission.
A similarity index counts text in your document that matches text elsewhere. It counts matches regardless of whether you did anything wrong. That includes:
- Correctly quoted and cited material. A properly referenced direct quotation still registers as matching text.
- Your reference list. Dozens of author names, titles and journal names that legitimately match other documents.
- Standard phrases. “The purpose of this study is to examine the effect of” matches thousands of documents and belongs to nobody.
- Your own earlier work, including a proposal or seminar paper you submitted previously.
The consequence runs both ways. A report at 22% can be entirely honest work with a long reference list. A report at 8% can contain a stolen, unattributed idea that no software will ever flag, because paraphrased theft produces no matching string. The number measures overlap, not dishonesty. A human being reads the report and decides.
Do these rules apply to my undergraduate final year project?
Not directly, and you should be careful here. All three documents quoted above govern higher degrees — master’s and doctoral work submitted to a postgraduate school or college.
Undergraduate final year projects are governed by your department’s guidelines. Some departments apply the postgraduate threshold by analogy, some set their own, and some have no numeric rule and rely on the supervisor’s judgement. There is no way to know which of those describes your department except by asking.
How do I find the rule that actually binds me?
- Ask for the document by name. Request your department’s project guidelines and, if you are a postgraduate, your school or college’s thesis guidelines. Ask for the current edition — OAU’s is dated January 2026 and UI’s was revised in 2023, so editions do move.
- Ask who runs the check and when. At Covenant the Centre for Learning Resources runs it and evidence must accompany submission. Knowing the stage matters: a check that happens at submission leaves you no time to fix anything.
- Ask what counts. Whether the reference list and quoted material are excluded from the reported figure changes the number substantially, and departments differ.
- Ask what happens above the line. Rejection, resubmission, referral to a committee — these are not the same outcome, and the published policies name specific consequences.
- Get it in writing. A number quoted verbally by a course mate is how students end up confidently wrong.
What should I actually do to keep the score honest?
- Reference as you write, not at the end. Almost every genuine plagiarism case in student work starts as a citation someone meant to add later.
- Quote sparingly and deliberately. If a passage is worth quoting directly, quote and cite it. If it is not, put it in your own words and still cite the source of the idea.
- Cite ideas, not just sentences. A paraphrase without a citation is still plagiarism, and it is the form software misses and examiners catch.
- Keep your own record of sources from day one, so you are never reconstructing where a paragraph came from three months later.
- Treat any pre-check as a draft signal. Only your institution’s official check counts.
Frequently asked questions
Is 20% the acceptable plagiarism rate in Nigeria?
It is the published limit at Covenant University for postgraduate theses. It is not a national rule, and other institutions publish no percentage at all.
Do Nigerian universities check projects for plagiarism?
Institutions that publish policies describe formal checks. Covenant University requires a plagiarism test carried out by its Centre for Learning Resources, with evidence submitted alongside the thesis. Whether your specific department checks undergraduate projects is a departmental question.
What happens if my similarity score is too high?
It depends on the policy that binds you. Covenant University’s handbook states that any percentage above its threshold shall be rejected, and that plagiarism discovered after a degree has been awarded attracts immediate withdrawal of the degree.
Does a 0% similarity score mean my work is safe?
No. Software detects matching text. An unattributed idea expressed in your own words produces no match and is still plagiarism.
Does my reference list count towards the percentage?
That depends on how the check is configured at your institution. Ask whether references and quoted material are excluded before you interpret any number.
Can I use the same content from my seminar paper?
Reusing your own submitted work without disclosure is treated as an integrity issue at many institutions. Declare it to your supervisor rather than assuming it is free.
Is there an NUC-approved plagiarism percentage?
No single national percentage is published in the Commission’s public materials. Treat any claim of an NUC percentage as requiring a source you can open.
Does a signed declaration replace a similarity check?
At OAU the declaration is a required preliminary page in its January 2026 guidelines. Whether a check also runs is a separate institutional process — the declaration is a personal undertaking, not an exemption.
Are undergraduate projects held to the same standard as theses?
The published thesis guidelines govern higher degrees. Undergraduate projects follow departmental rules, which vary and must be requested directly.
Write it so the number never matters
Every student who panics about a similarity score is really asking a different question: have I written this myself? If you have built the argument, referenced the sources as you went and put other people’s ideas in your own words with attribution, the report is a formality rather than a verdict.
Tesify helps you draft chapters, keep your citations attached to the sentences that need them, and check your own work before your department does — 100% written by you, alongside 9,000+ students and 15,000+ chapters.