A guide to self-plagiarism for students and academics

Plagiarism often involves using someone else’s words or ideas without proper citation, but you can also plagiarize yourself.

Self-plagiarism means reusing work that you have already published or submitted for a class. It can involve re-submitting an entire paper, copying or paraphrasing passages or excerpts, or recycling previously-collected data.

Self-plagiarism misleads your readers by presenting previous work as completely new and original. If you want to include any text, ideas, or data that you already submitted in a previous assignment, be sure to inform your reader by citing yourself.

To ensure your text doesn’t contain unintentional self-plagiarism, get your document checked before submission by specialized self-plagiarism software, such as our Own Sources Checker.

For students: Self-plagiarism in college

While self-plagiarism may not be considered as serious as plagiarizing someone else’s work, it is still a form of academic dishonesty. Your academic institution may not accept your work if you recycle your own previous assignments.

Examples of self-plagiarism by students

You may be committing self-plagiarism if you:

  • Submit an assignment from a previous academic year to a current class.
  • Tweak a paper you wrote in high school and resubmit it in a university course.
  • Recycle parts of an old assignment without citing it, such as copying-and-pasting sections or paragraphs from previously-submitted work.
Submitting the same paper to two classes
You are studying the battles of World War II in both a literature class and a history class, and a writing assignment asks you to choose a battle to analyze. You may think you are saving time by submitting variations on the same paper to both courses, but in fact you are committing self-plagiarism.
Reusing passages from a previous paper
You are working on your capstone project, your last big assignment before graduation. You have chosen to write a thesis about the effects of Brexit on European commerce. You already wrote a paper about Brexit for a previous course, so you may not see any harm in reusing a section or two in your thesis. However, if you don’t cite yourself, you are committing self-plagiarism.

For academics: Self-plagiarism in published works

Self-plagiarism in academia has ethical and legal implications. Published research is expected to make a new and original contribution to knowledge, so recycling your old work undermines academic integrity. Your journal submissions will likely be rejected if you self-plagiarize.

Examples of self-plagiarism by academics

You may be committing self-plagiarism if you:

  • Use a dataset from a previous study (published or not) without letting your reader know.
  • Submit a manuscript for publication containing data, conclusions, or passages that have already been published without citing your previous publication.
  • Publish multiple similar papers about the same study in different journals.
Simultaneous submission
You have conducted research on the effects of the recent elections on policy initiatives. You submit your findings to all relevant academic journals, hoping someone picks it up. You may think you are broadening your chances of getting published, but in fact you are at risk of committing self-plagiarism if multiple journals opt to publish your research.
Recycling data
You are working on a new paper about military spending, and realize that a portion of a dataset that you used in a previously-published paper would really enhance your current dataset. Since it’s your data, you don’t see any harm in adding it to your new dataset. However, if you don’t cite yourself, you are committing self-plagiarism.

Check for self-plagiarism

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Consequences of self-plagiarism

For students

Many universities treat self-plagiarism the same way they treat other types of plagiarism, with the same consequences for committing it.

At most universities, plagiarism results in an automatic zero on the assignment, and sometimes an automatic failing grade in the course. More serious consequences involve academic probation or even expulsion.

If you reuse a previously-submitted assignment, you are also hurting your learning process. Each course has something different to teach you, and resubmitting an old assignment means you aren’t learning anything new.

Some university departments do allow you to reuse previous work under certain circumstances. Make sure you fully understand the policy to avoid facing unintended consequences. If your university allows you to reuse elements of your old work, be sure to check with your professors and get permission before doing so.

For academics

The consequences for an academic or researcher who self-plagiarizes can be quite severe, ranging from delayed or rejected publication to copyright infringement.

If your article is too similar to one of your previously published works, the journal is likely to reject it outright, or require extensive edits to your submission. This impacts your reputation as a researcher and may lead to future rejections.

Even if the journal allows resubmissions of previously published work, be sure to check whether the original publisher owns the copyright of your paper. If you publish large portions of the same material elsewhere (even with a citation), you may be infringing copyright, which could have legal consequences. If you had a co-author, be sure to get their permission prior to resubmitting, and give them appropriate credit in the citation. Not doing so could constitute fraud.

How do educational institutions detect self-plagiarism?

In addition to plagiarism software databases, many educational institutions keep databases of submitted assignments. Sometimes, they even have access to databases at other institutions. If you hand in even a portion of an old assignment a second time, the plagiarism software will flag it as self-plagiarism.

Online plagiarism checkers not affiliated with a university do not have access to the internal databases of educational institutions, and therefore their software cannot check your document for self-plagiarism.

In addition to our Plagiarism Checker, Scribbr also offers an Own Sources Checker. This unique tool allows you to upload your own original sources and compare them with your new assignment. It will flag any unintentional self-plagiarism, in addition to other forms of plagiarism, and helps ensure that you add the correct citations prior to submitting your assignment.

How to avoid self-plagiarism

If you’re unsure whether something counts as self-plagiarism, first check the relevant plagiarism policy, whether for your university, the journal or publishing house you are submitting to, or your academic department. Plagiarism policies can often be found in the honor code, handbook, or submission requirements.

If there is no explicit policy on self-plagiarism, follow these guidelines.

For students

  • Do not reuse your old assignments. It is likely that at some point in your academic career you will be assigned a topic that you’ve already researched. Never submit the same paper again, even if it’s for a completely different course or school.
  • Talk to your instructor if you want to cover some of the same ideas in your new paper. They can tell you whether it’s acceptable to reuse or rework parts of old assignments.

For academics

  • Do not reuse previously published work. Reusing part of an already-published text in a new work could constitute copyright infringement, and misleads readers. To avoid this, make sure every part of your paper is original and written from scratch.
  • If you use old data or ideas, always inform the reader. You might want to build on research you’ve published elsewhere. As long as you use the material in a new and original way, and you properly cite the publication where it originally appeared, this is generally acceptable.

How to cite yourself

You can cite yourself just like you would cite any other source. Be sure that you have permission from your instructor to reuse previous content before doing so, and indicate in your citation if the source is unpublished.

Example: Citing an unpublished thesis
Format Last name author, Initials. (Year). Title. [Unpublished type of thesis or dissertation]. Name of University. URL/DOI
Citation (bibliography) Merkus, J. (2018). The power of reading: The effect of different reading methods on the vocabulary of multilingual children. [Unpublished master’s thesis]. Radboud University.
Text Reference (Merkus, 2018)
Format Last name, First name (Year): “Title.” Place of Study, Year. Title of Database. Web. Date Month Year of Access.
Citation (bibliography) Merkus, Julia (2018): “The Power of Reading: the Effect of Different Reading Methods on the Vocabulary of Multilingual Children.” Radboud University, 2018. Web. Accessed October 2021.
Text Reference (Merkus, page)
Format Last-name, First-name. Year. “Title of Thesis: Subtitle.” Unpublished thesis type. University.
Citation (bibliography) Merkus, Julia. 2018. “The Power of Reading: The Effect of Different Reading Methods on the Vocabulary of Multilingual Children.” Unpublished master’s thesis. Radboud University.
Reference (Merkus, 2018)

Scribbr’s Own Sources Checker for self-plagiarism

Online plagiarism scanners do not have access to internal university databases, and therefore cannot check your document for self-plagiarism.

Using Scribbr’s Own Sources Checker, you can upload your previous work and compare it to your current document:

  • Your thesis or dissertation
  • Your papers or essays
  • Any other published or unpublished documents

The checker will scan the texts for similarities and flag any passages where you might have self-plagiarized.

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Frequently asked questions

Can you plagiarize yourself?

Yes, reusing your own work without citation is considered self-plagiarism. This can range from re-submitting an entire assignment to reusing passages or data from something you’ve turned in previously.

Self-plagiarism often has the same consequences as other types of plagiarism. If you want to reuse content you wrote in the past, make sure to check your university’s policy or consult your professor.

When do you need to cite yourself?

If you are reusing content or data you used in a previous assignment, make sure to cite yourself. You can cite yourself the same way you would cite any other source: simply follow the directions for the citation style you are using. 

Keep in mind that reusing prior content can be considered self-plagiarism, so make sure you ask your professor or consult your university’s handbook prior to doing so.

Is plagiarism illegal?

Plagiarism has serious consequences, and can indeed be illegal in certain scenarios.

While most of the time plagiarism in an undergraduate setting is not illegal, plagiarism or self-plagiarism in a professional academic setting can lead to legal action, including copyright infringement and fraud. Many scholarly journals do not allow you to submit the same work to more than one journal, and if you do not credit a co-author, you could be legally defrauding them.

Even if you aren’t breaking the law, plagiarism can seriously impact your academic career. While the exact consequences of plagiarism vary by institution and severity, common consequences include: a lower grade, automatically failing a course, academic suspension or probation, or even expulsion.

When should I use the Own Sources Checker instead of the Scribbr Plagiarism Checker?

The Scribbr Plagiarism Checker compares your document against the largest content database in the world. It will detect any similarities with documents in that database.

However, you might be unsure if all of the sources you used are in that database – for example, because some of your sources are unpublished. In this case, you can make use of our Own Sources Checker. Here you can add all the sources you want to a private database and compare them with your own document.

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Tegan George

Tegan is an American based in Amsterdam, with master's degrees in political science and education administration. While she is definitely a political scientist at heart, her experience working at universities led to a passion for making social science topics more approachable and exciting to students. A well-designed natural experiment is her favorite type of research, but she also loves qualitative methods of all varieties.