Do I need permission from the conference to publish an extension?

Usually not from the conference itself, though the copyright question still matters. IEEE, for example, lets authors reuse portions of their own published work in a later article if they cite the original and mark recycled material; larger reuse means contacting the publisher's permissions office. What you always owe is disclosure: name the conference paper in your references and explain the overlap in your cover letter.

From Conference Paper to Journal: Picking a Venue for the Extension.

Q: How much of a conference paper can I reuse?

Reuse is allowed; the limit is on how little you add. ACM policy accepts republication only when at least 25% of the material was not previously published, and several IEEE journals ask for around 30% new content. Reusing your own text, figures, and tables is fine when you cite the conference version and clearly mark what was recycled.

Waraq · August 5, 2026 · JOURNAL SELECTION

Extend a conference paper into a journal article by choosing a journal that accepts extended proceedings work first. Then add enough new material to clear that journal's threshold, and disclose the earlier version in your cover letter and reference list. Publishers set the threshold differently: ACM policy asks for at least 25% material not previously published, and several IEEE journals ask for around 30%. Pick the venue before you write the extension, because the venue decides how much you must add and how you must credit the proceedings paper.

That order is what most authors get backwards. They expand the paper to whatever length feels complete, submit it, and then discover the target journal counts new material differently than they assumed. A proceedings paper is short by design, so the temptation is to treat any longer version as an extension. Journals do not.

When does a conference paper deserve a journal extension?

When there is real work the proceedings page limit forced you to cut, or when the project has moved since the conference. If the conference version already said everything you know, a journal extension turns into padding, and reviewers notice.

Proceedings papers run short: a few pages, a compressed method, results trimmed to fit. A strong candidate for extension usually has experiments that never made the deadline, a dataset that has since grown, or an analysis you could only gesture at in the talk. Those gaps are the raw material for the new version. A paper that was complete at the conference, by contrast, has nowhere to grow, and stretching it to journal length is the kind of submission editors decline quickly.

How much new material do journals expect?

Most publishers set a floor, and it is a floor rather than a target. ACM policy accepts a republished work only when at least 25% of it is material not previously published. Several IEEE journals ask for around 30% new content.

The exact number is the publisher's to name, so read the one you are aiming at. IEEE Power and Energy Society asks extended papers to add at least 60% new material relative to the conference version, well above the common figure. The IEEE Communications Society takes the opposite approach and sets no percentage at all, requiring only that the manuscript hold a significant amount of new material beyond the conference paper. Treat whatever number appears as the minimum, and make the new content substantive: fresh experiments, a deeper analysis, a proper related-work review. Padding the introduction to hit a percentage fools no reviewer who knows the conference paper.

How do you find journals that welcome extended versions?

Start with the journals tied to your conference. Many run special sections that invite extended versions of the best proceedings papers, and those venues expect the conference lineage you are worried about disclosing.

Beyond that route, the author guidelines tell you plainly. Look for a statement about prior conference publication in the submission policy; a journal that accepts extensions almost always says so. If the guidelines are silent, the aims and scope page and the recent issues will show whether extended proceedings work fits, and there is a method for reading aims and scope as a filter rather than a slogan. When the conference has no partner journal, the same shortlist approach used for any first paper applies: score candidates on scope fit, then confirm each one accepts prior conference publication before you commit.

How do you disclose the earlier paper without a self-plagiarism problem?

Cite the conference paper in your reference list, describe the overlap in your cover letter, and mark every reused passage, figure, and table. Self-plagiarism means reusing your own published text without disclosure, and disclosure is the entire fix.

Reusing your own work is not the offense; hiding it is. IEEE lets authors reuse portions of their own published material in a later article, provided they cite the original publication and clearly indicate what was recycled, with larger reuse handled by the publisher's permissions office. So the copyright question usually resolves in your favor as the author. What editors want is a clear account: which results are new, which appeared at the conference, and how the two versions differ. Put that account in the cover letter, where reviewers can read it, and a cover letter written for the editor is the right place to state it in two or three sentences. Before you submit, it helps to check the manuscript against the target journal's own rules, including its policy on prior publication, so the disclosure matches what that journal asks for.

What changes when you move from proceedings format to a full article?

The paper grows in the sections proceedings compress. A journal version needs a fuller introduction, an expanded method a reader could reproduce, and a discussion section that proceedings rarely have room for.

Related work is usually the first section to double, because a talk can assume its audience and a journal cannot. The method section carries the reproduction burden, so detail you skipped for the conference belongs here in full. Then there is the mechanical work: the reference style almost never matches between a proceedings template and a journal, so plan to reformat every citation to the target style, whether that is numbered by appearance or alphabetical by author. Running the finished draft through a first-submission checklist catches the files and statements the longer format now requires.

When should you time the extension?

Submit after the conference, once the talk has drawn questions worth answering, but leave real runway before any deadline that depends on the paper. Journal review takes months, not weeks.

The conference is useful before you extend, not just as a milestone. Questions from the session often point to the exact analysis the journal version needs, and a reviewer's later objection is easier to answer when you have already heard it in the room. Against that, weigh your own clock. If a defense date or a job application rests on the article, count backward from it: a first decision can take several months, and a revision adds more. Whatever the timeline, submit to one journal and wait. Sending the same manuscript to two journals at once is the shortcut that ends every version of the paper.