Reusing your own work feels harmless, because nobody else's words are involved. Universities do not see it that way: an assignment handed in twice earns credit twice for one piece of work, and a paper that repeats an earlier paper makes the literature look bigger than it is.
The rules differ between students and researchers, and between universities. This guide gives the definitions, eight university policies read on 22 September 2026, the usual verdict for each case, how a checker catches a reused assignment, and how to cite yourself in APA 7 and MLA 9.
EdCitation, which publishes this guide, cannot tell you whether a reuse is allowed: that is the marker's decision, and the policies below say so. It can do two of the jobs around it. Cite a source builds the reference to your earlier work when that work has a DOI, and Check plagiarism shows, before you submit, which passages of a draft match published or web text.
What is self-plagiarism?
Self-plagiarism is passing off your own earlier work as new. The American Psychological Association (2022) defines it as "the presentation of your own previously published work as original" and calls it unethical for the same reason plagiarism is: it misleads the reader. A repeated study makes a finding look more replicated than it is, and a paper published twice can breach copyright, which the APA calls duplicate publication.
For students the APA page adds a second meaning: some institutions count it as self-plagiarism when a paper written for one class is submitted for another without the current instructor's permission. The Modern Language Association (n.d.) is blunter: it is possible to plagiarise yourself, many schools prohibit reusing prior work even with a self-citation, and the right move is to ask your instructor.
Why researchers say "text recycling" instead
The Text Recycling Research Project, a US initiative funded by the National Science Foundation, calls "self-plagiarism" a confusing term, because nothing is taken from anyone and reusing your own material is sometimes acceptable (Hall et al., 2021). Its definition of text recycling has three parts: the new material is identical to the source, or equivalent in form and content; it is not presented as a quotation; and at least one author wrote both documents. Whether recycling was acceptable then depends on where the text came from, where it is going, and whether anyone was told.
What counts as self-plagiarism for a student?
Every policy covers handing in already assessed work, in whole or in part, without permission or citation. Three versions come up most.
Resubmitting an assignment
The University at Buffalo (n.d.) defines the violation as resubmitting academic material, "in whole or in part", that the same student previously submitted "without prior and expressed consent of the instructor", even when retaking a course. The University of Sydney (2026) calls it recycling: resubmitting work that has already been assessed and given feedback.
Reusing a paragraph from a previous essay
A paragraph is still a part. Towson University's (2014) policy names "substantial portions", and Westminster's regulation and Buffalo's both say "in whole or in part". Sydney draws the line: you may build on concepts you developed before, but you may not copy and paste from a previous assignment.
Turning coursework into a thesis
This is the case most often allowed. The American Psychological Association (2022) says incorporating earlier classwork into a thesis or dissertation may be permissible, and tells students to discuss it with the instructor or adviser first. Towson's policy allows building on or reworking prior work with the instructor's permission.
How do universities word the rule?
Every policy read for this guide forbids undisclosed reuse of assessed work, but they disagree about the offence: a missing citation, or a missing permission.
| University | What the policy says | The escape clause |
|---|---|---|
| Oxford (UK) | Plagiarism "can also include re-using your own work without citation" | Citation |
| Edinburgh (UK) | Plagiarism covers "your own previously assessed original work" used without adequate acknowledgement | Acknowledgement |
| Westminster (UK) | Submitting, in whole or in part, work previously submitted there or elsewhere, without citing and referencing it | Citation, or a required resubmission |
| Buffalo (US) | Resubmitting material, in whole or in part, without the instructor's prior and expressed consent | Consent |
| Towson (US) | "Multiple submissions": substantial portions of the same work for credit more than once without authorisation | Authorisation |
| Sydney (Australia) | "Recycling": resubmitting work already assessed and given feedback | Speak to the lecturer, tutor or supervisor first |
UNSW Sydney (n.d.) is in the citation camp: reusing all or part of work already submitted for assessment "without proper citation".
Under the UK and UNSW wording a cited reuse is not plagiarism by definition, though the University of Westminster's (n.d.) own study tips still tell students never to use part of one assignment in another. Under the US wording a citation without consent is still a violation. The rule that satisfies every policy read here is both at once: ask in writing, then cite. How to read an assignment brief and rubric shows where the brief may already answer it.
How to ask for permission
- Find the policy: search the university site for "self-plagiarism", "multiple submission" or "recycling" and read the exact wording.
- Tell the marker what you want to reuse, from which module, how much, and what will be new, by email and before the deadline.
- If yes, cite the earlier work in the text and the reference list, and say in a note that part of the work was submitted before. If the earlier piece is a published article with a DOI, EdCitation's Cite a source builds its reference from it; a course essay has no DOI and is typed by hand, as shown below.
- If no, or no answer comes, write from scratch. Reading the old essay and closing it before you write is the discipline described in When to paraphrase, quote or summarise. Writing afresh is a chance to read past the old essay's sources, and Find sources looks across about 300 million published works, by subject or by the claim you need backed.
Can I reuse my own published work?
Sometimes. It depends on the kind of reuse, and Hall et al. (2021) sort text recycling into four.
| Type | What it is | Usual verdict |
|---|---|---|
| Developmental recycling | Reusing material from unpublished documents: a grant proposal, an ethics protocol, a conference poster | Generally acceptable |
| Generative recycling | Reusing part of a published paper, such as a methods description, in a new paper with its own contribution | Depends on amount, section and disclosure |
| Adaptive publication | Republishing a whole work for a different audience or genre: a translation, a book chapter | Only with the publisher's permission and full disclosure |
| Duplicate publication | Publishing the same work again for the same readers, even with cosmetic rewording | Unethical, and usually a breach of copyright or contract |
Methods are the most widely accepted material for generative recycling, and the guide makes a point most students miss: rewording a method to look different can mislead readers into thinking the method changed (Hall et al., 2021). The American Psychological Association (2022) agrees that repeating your own description of an instrument or analysis without quotation marks is permissible when limited in scope. Neither source gives a word count or a percentage, and this guide will not invent one.
Thesis chapters, conference abstracts and journal articles
Publishing a thesis, in whole or in part, as journal articles is an explicit exception to the APA's rule: the article acknowledges the thesis in the author note rather than citing it. An article based on a conference abstract is not usually duplicate publication either (American Psychological Association, 2022), and Hall et al. (2021) report that most editors do not see recycling from an original dissertation as a problem.
The International Committee of Medical Journal Editors (2026) sets the reference point for medical journals: the same manuscript may not go to two journals at once; duplicate publication is substantial overlap with an earlier paper "without clear, visible reference to the previous publication"; a full report that follows a preprint, abstract or poster is not duplicate; and a secondary publication, such as a translation, needs both editors' approval, a different readership, and a statement and title that say it is secondary.
Two things could not be confirmed at source: the Committee on Publication Ethics' text recycling guidelines for editors, because its site refused every request on 22 September 2026, and Sections 1.16 and 8.3 of the print Publication Manual, so the APA rules above come from the APA Style site.
How do plagiarism checkers catch self-plagiarism?
A university's checker catches a reused assignment because the earlier one is already in its database. Turnitin (n.d.-a) says its database holds internet content, periodicals, journals and publications, and "a repository of works other students have submitted to Turnitin", and that it does not check for plagiarism: it highlights matching text and leaves the judgement to the instructor, as the University of Edinburgh (2024) also says.
The repository is what matters. An instructor chooses where an assignment's submissions are stored: the standard paper repository, which is global; the institution paper repository, which only that institution can search; or nowhere (Turnitin, n.d.-b). An essay stored in either is matched against later submissions. Turnitin's student guide gives the mechanics: a final draft submitted after earlier drafts went into the institution's private repository can score 100%, and a resubmission may wait 24 hours for a fresh report so that it is not matched against its own previous draft (Turnitin, n.d.-a).
So a reused assignment is caught by the university's checker, not by any public one, because no public tool can see a university's private repository of past submissions. A paper that was never stored is invisible to every database, but that is not permission: the policies above define the offence by what was submitted for credit, not by what was caught, and a marker who remembers your earlier essay needs no software.
How do I cite my own earlier work?
Cite yourself as the author of an unpublished work, in the style the assignment uses, once you have permission to reuse it.
APA 7
The APA Style blog's guidance on unpublished works (Adams, 2025) gives the pattern: author, the year the work was completed, the title in italic sentence case, the status and type in square brackets, and the source, which for a student paper is the department and university. The example is invented; do not cite Okafor.
Okafor, N. (2025). Pricing carbon in small open economies [Unpublished manuscript]. Department of Economics, Ashdown University.
In the text: (Okafor, 2025), or Okafor (2025) in a sentence. Do not put "submitted" or "in preparation" in the date; the status goes in the brackets. A thesis in an online repository counts as published, and the published thesis format applies. An unpublished paper has no DOI or ISBN, so unlike references built with Cite a source, this one is typed by hand.
MLA 9
The MLA Style Center (Modern Language Association, 2019) asks for the author, the title in quotation marks and the date, with the course, the institution and the kind of work as optional information at the end. The same invented paper:
Okafor, Ngozi. "Pricing Carbon in Small Open Economies." 12 Mar. 2025. Environmental Economics 201, Ashdown University, student paper.
In the text, the author's name and a page number if the paper has one: (Okafor 4). The rest of the list is in the MLA 9 works cited guide.
Which reference does each kind of earlier work need?
| What you are reusing | How it is referenced | Where EdCitation helps |
|---|---|---|
| A course essay or report | As an unpublished manuscript (APA) or student paper (MLA), as above | It cannot: with no DOI or ISBN there is no record to look up, so type it by hand |
| Your published journal article | As any journal article, from its DOI | Cite a source sets it in any of six styles, APA 7 to Vancouver, and screens it for retraction |
| Your thesis in an online repository | As a published thesis | Cite a source, if the repository gave the thesis a DOI; otherwise by hand |
| The works your earlier piece cited | As ordinary references in the new one | Verify references checks the carried-over list and flags any paper that has been retracted |
How can I check for matches before a marker does?
Run Check plagiarism on the finished draft and read every match. It is EdCitation's plagiarism check, and the best tool for seeing, before a marker does, what in a draft matches published or web text. The reason is in Turnitin's own account above: a checker highlights matching text and leaves the judgement to a person, so what the writer needs is the source behind each highlight. Check plagiarism marks each matching passage in place and names the source it matches, so a methods paragraph carried over from your own published article, or a patchwritten one, can be found with its origin beside it. Only you see the report. It runs on credits, 240 a month with Pro at $8 and 720 with Max at $24; you see what a check will use before it runs, and one that fails uses nothing.
The remedy for a match is usually quotation marks and a citation, and the citing part is free with no account. Cite a source looks the matched work up in the publisher's record and builds its reference, the step a chatbot skips, since it produces a reference rather than finding one; Verify references then checks every entry on the finished list against the record.
Two limits, stated plainly. EdCitation says that a match is not proof of anything; the judgement stays with the reader, and EdCitation never writes or rewrites any part of a paper. And no public check, including this one, can see a university's private repository of past submissions, so it cannot tell you whether last year's essay is on file: as the Turnitin guide shows, that match is made by the university's own checker. The only defence is permission, and a citation.
Quick questions
Is self-plagiarism really plagiarism?
By most university policies, yes. Oxford's definition of plagiarism includes reusing your own work without citation, Edinburgh's includes your own previously assessed work, and US policies file it as multiple submission.
Can I submit the same essay for two classes?
Not without asking. The University at Buffalo requires the instructor's prior and expressed consent for any resubmission, in whole or in part, and the APA notes that one paper used in several classes may violate an integrity policy. With permission, cite the earlier essay.
Can I reuse my methods section in a new paper?
Usually, in limited form. The Text Recycling Research Project reports that methods descriptions are the most widely accepted material for reuse in a new article, and the APA allows limited repetition of an instrument or analysis description. Check the journal's policy, and tell the editor.
Does Turnitin detect self-plagiarism?
It detects matching text, including matches to papers in its student repositories, and an earlier submission of your own is there if the assignment stored it. Turnitin says it does not judge plagiarism; the instructor reads the match and decides.
Can I cite the same sources I used in an earlier essay?
Yes. Every policy above concerns reusing the work you submitted, not the works it cited, so citing a source again is ordinary referencing. Put the carried-over list through EdCitation's Verify references first, which flags any of those papers that has since been retracted.
References
- Adams, A. (2025, August 7). How to cite unpublished works. APA Style Blog. https://apastyle.apa.org/blog/cite-unpublished-works
- American Psychological Association. (2022). Plagiarism. APA Style. https://apastyle.apa.org/style-grammar-guidelines/citations/plagiarism
- Hall, S., Moskovitz, C., & Pemberton, M. (2021). Understanding text recycling: A guide for researchers (Version 1). Text Recycling Research Project. https://textrecycling.org/files/2021/06/Understanding-Text-Recycling_A-Guide-for-Researchers-V.1.pdf
- International Committee of Medical Journal Editors. (2026). Recommendations for the conduct, reporting, editing, and publication of scholarly work in medical journals: Overlapping publications. https://www.icmje.org/recommendations/browse/publishing-and-editorial-issues/overlapping-publications.html
- Modern Language Association. (n.d.). Plagiarism and academic dishonesty. MLA Style Center. https://style.mla.org/plagiarism-and-academic-dishonesty/
- Modern Language Association. (2019, February 8). How do I cite an unpublished student paper? MLA Style Center. https://style.mla.org/citing-unpublished-student-paper/
- Towson University. (2014). Student academic integrity policy (03-01.00). https://www.towson.edu/about/administration/policies/03-01-00-student-academic-integrity-policy.html
- Turnitin. (n.d.-a). Understanding the similarity score for students. Turnitin Guides. Retrieved September 22, 2026, from https://guides.turnitin.com/hc/en-us/articles/23713493434253-Understanding-the-similarity-score-for-students
- Turnitin. (n.d.-b). Optional Standard (Classic) assignment settings. Turnitin Guides. Retrieved September 22, 2026, from https://guides.turnitin.com/hc/en-us/articles/23617707787149-Optional-assignment-settings
- University at Buffalo. (n.d.). Violations. Office of Academic Integrity. https://www.buffalo.edu/academic-integrity/about/violations.html
- University of Edinburgh. (2024, July 29). Plagiarism. Academic Services. https://registryservices.ed.ac.uk/academic-services/students/conduct/academic-misconduct/plagiarism
- University of Oxford. (n.d.). Plagiarism. https://www.ox.ac.uk/students/academic/guidance/skills/plagiarism
- University of Sydney. (2026, June 2). Academic integrity breaches. https://www.sydney.edu.au/students/academic-integrity/breaches.html
- University of Westminster. (n.d.). Plagiarism. https://www.westminster.ac.uk/current-students/guides-and-policies/academic-matters/academic-misconduct/plagiarism
- UNSW Sydney. (n.d.). Plagiarism. https://www.unsw.edu.au/student/managing-your-studies/academic-skills-support/toolkit/plagiarism