Competing Interests

The following policy applies to all of PLOS journals, unless otherwise noted.

What Represents a Competing Interest?

A competing interest is anything that interferes with, or could reasonably be perceived as interfering with, the full and objective presentation, peer review, editorial decision-making, or publication of research or non-research articles submitted to PLOS.

Competing interests can be financial or non-financial, professional, or personal. Competing interests can arise in relationship to an organization or another person.

Declaring all potential competing interests is a requirement at PLOS and is integral to the transparent reporting of research.

Failure to declare competing interests can result in immediate rejection of a manuscript. If an undisclosed competing interest comes to light after publication, PLOS will take action in accordance with COPE guidelines and issue a public notification to the community. 

What to Declare

All potentially competing interests (see below) must be declared if they occurred within 5 years of conducting, or preparing for publication, the research under consideration.

Interests outside the 5-year time frame must also be declared if they could reasonably be perceived as competing according to the definition above.

Financial competing interests

Financial competing interests include but are not limited to:

  • Ownership of stocks or shares

  • Paid employment or consultancy

  • Board membership

  • Patent applications (pending or actual), including individual applications or those belonging to the institution to which the authors are affiliated and from which the authors may benefit

  • Research grants (from any source, restricted or unrestricted)

  • Travel grants and honoraria for speaking or participation at meetings

  • Gifts

Non-financial competing interests

Non-financial competing interests include but are not limited to:

  • Acting as an expert witness

  • Membership in a government or other advisory board

  • Relationship (paid or unpaid) with organizations and funding bodies including nongovernmental organizations, research institutions, or charities

  • Membership of lobbying or advocacy organizations

  • Writing or consulting for an educational company

  • Personal relationships (i.e. friend, spouse, family member, current or previous mentor, adversary) with individuals involved in the submission or evaluation of a paper, such as authors, reviewers, editors, or members of the editorial board of a PLOS journal

  • Personal convictions (political, religious, ideological, or other) related to a paper's topic that might interfere with an unbiased publication process (at the stage of authorship, peer review, editorial decision-making, or publication)

Who Must Declare Competing Interests?


At the time of submission, authors must state what competing interests are relevant to the submitted research. These may include but are not limited to:

  • Names of all funding sources

  • Description of funder’s role in the study design; collection, analysis, and interpretation of data; writing of the paper; and/or decision to submit for publication

  • Whether they have served or currently serve on the editorial board of the journal to which they are submitting

  • Whether they have acted as an expert witness in relevant legal proceedings

  • Whether they have sat or currently sit on a committee for an organization that may benefit from publication of the paper

Editors and reviewers

Editors (professional or academic, paid or unpaid) and reviewers must declare their own competing interests and if necessary disqualify themselves from involvement in the assessment of a manuscript.

Common reasons for editors and reviewers to recuse themselves from the peer review process may include but are not limited to:

  • They work at the same institution or organization as an author, currently or recently

  • They collaborate with an author, currently or recently

  • They have published with an author during the past 5 years

  • They have held grants with an author, currently or recently

  • They have a personal relationship with an author that does not allow them to evaluate the manuscript objectively


Anyone who comments on published PLOS articles must declare all competing interests (financial or non-financial) at the time of posting the comment.

Editorial Actions and Decisions

  • PLOS editors must take all competing interests into account during the review process and ensure that any relevant ones are declared in the published article.

  • PLOS editors will not publish commissioned or any other non-research articles if they are aware of a competing interest that, in their judgment, could introduce bias or a reasonable perception of bias.

  • PLOS editors do not consult reviewers who have competing interests that, in the editors' judgment, could interfere with unbiased review. 
See this editorial for further clarification of our position on competing interests: PLOS Medicine Editors (2008) Making Sense of Non-Financial Competing Interests. PLOS Med 5(9): e199 doi:10.1371/journal.pmed.0050199.