How long should the justification be?

Two or three sentences. The editor is deciding whether to spend an invitation on this person, and the useful content is the specific overlap with your methods plus the absence of conflict. Anything longer is rarely read.

Can I suggest someone I have met at a conference?

Usually yes. Having met someone is not a conflict of interest in any publisher policy we are aware of. Having co-authored with them, worked at the same institution, supervised them or held a grant with them is. If you are unsure whether an acquaintance crosses the line, the safe move is to name someone else.

Will the editor tell me whether they used my suggestions?

No. Reviewer identities stay confidential under single-blind and double-blind review, so you will not learn whether any suggested name was invited or accepted. Elsevier states that the editor retains sole discretion, MDPI warns that its editors will not necessarily approach them, and Scientific Reports says it is not obliged to follow the recommendations.

Is it acceptable to suggest reviewers I have cited?

Yes, and it is common, because the people who work closest to your problem are usually in your reference list. Citing someone is not a conflict. Having published with them is, so check the author lists of the papers you cite rather than only the citations themselves.

Reviewer Suggestion Letter Templates

Three copyable formats for the suggested reviewers field: one entry per candidate, a cover letter paragraph, and a request to exclude someone. Each is annotated with what makes it work.

A reviewer suggestion is a short piece of writing with one job: give the editor enough to decide, in one reading, that the person you named is both qualified and unconflicted. Most authors write a single line that says the candidate is an expert in the field, which tells the editor nothing they could not have guessed. The templates below are the three formats submission systems actually ask for, with the justification written the way an editor can use it. If you do not yet have candidates, our reviewer finder reads your manuscript and suggests names with the overlap stated for each one, and the guide to suggesting reviewers covers how many names to give and where the field appears.

Variant 1: the per-reviewer form entry

Most submission systems ask for each suggested reviewer separately: name, affiliation, institutional email, and a free-text box for the reason. This is the format to copy when the system gives you one block per candidate. Fill it in once per name, and keep the reason to the two or three sentences an editor can read at a glance.

Per-reviewer entry

Name: Dr Amara Okonkwo
Affiliation: Department of Chemical Engineering, University of Leeds, United Kingdom
Email: a.okonkwo@leeds.ac.uk
ORCID: 0000-0002-1825-0097

Reason for suggestion:
Dr Okonkwo has published on membrane fouling in the same crossflow configuration used in our Methods section, and her 2025 study validated the flux-decline model our work extends. She is therefore positioned to judge whether our fouling measurements were made correctly, not only whether the topic is interesting.
We have never co-authored a publication, share no institutional affiliation, and have no current or past collaboration or funding in common.

Use the institutional email, never a personal one: editors treat a gmail address for an academic as a signal that the account may not belong to the person named, because that is how fake reviewer rings have worked.
Name the overlap with your methods, not your topic: an editor already knows the topic. What they cannot see is who can check the analysis.
Cite one specific piece of the candidate's work: a year and a claim is enough, and it proves you read them rather than searched a keyword.
State the absence of conflict explicitly: no co-authorship, no shared institution, no shared funding. If the journal names a window, such as three years, use its wording.
Add ORCID when the form has a field for it: it removes any ambiguity about which of two researchers with the same surname you mean.

Variant 2: the cover letter paragraph

Some journals have no dedicated field and expect the suggestions in the cover letter instead, and some accept them in both places. This variant compresses the same information into a paragraph that sits near the end of the letter, after the statement of originality and before the corresponding author details.

Cover letter paragraph

In line with the journal's author instructions, we suggest the following potential reviewers. None of them has co-authored with any of us, none shares our institutional affiliation, and none has been involved in the work reported here.

1. Dr Amara Okonkwo, University of Leeds, a.okonkwo@leeds.ac.uk. Published on membrane fouling in the crossflow configuration used in our Methods, and validated the flux-decline model this paper extends.

2. Prof. Hana Sato, Kyoto Institute of Technology, sato.hana@kit.ac.jp. Developed the impedance technique we adapted in Section 3, and can assess whether our adaptation is sound.

3. Dr Luis Marquez, Universidad de Chile, lmarquez@uchile.cl. Works on the same fouling problem in industrial rather than laboratory conditions, which is the applicability question our Discussion raises.

We leave the choice of reviewers entirely to the editor.

Number the entries: an editor copying names into a submission system works faster from a numbered list than from prose.; Put the shared no-conflict statement once at the top rather than repeating it three times, then keep each entry to two sentences.
Spread the list across countries and career stages: Springer Nature recommends a mix of countries and institutions, and some Cambridge University Press titles ask for at least three countries.
Close by deferring to the editor: it is their decision in every publisher policy we are aware of, and saying so costs nothing.; Do not repeat the paragraph in the form if you have already filled the form in, because a mismatch between the two lists creates work for the editorial office.

Variant 3: the request to exclude a reviewer

Most journals also let you name people you would rather they did not approach, in an opposed or excluded reviewers field, or in the cover letter when no field exists. Scientific Reports accepts up to three named individuals or laboratories and states that the exclusions will be honoured. Elsevier asks for a name, an institution and a reason, and notes that the person is shown your reason if they are invited anyway, which is the single best argument for writing it professionally.

Exclusion request

We respectfully request that the following individuals not be invited to review this manuscript.

1. Prof. [Name], [Institution]. Our group and theirs are currently working on the same research question with competing approaches, and a preprint from their laboratory addressing this question was posted in [month, year]. We would prefer that the evaluation of this work not sit with a direct competitor at this stage.

2. Dr [Name], [Institution]. A formal dispute over authorship on an earlier project, resolved through our institution's research integrity office in [year], makes an impartial review unlikely.

We make this request only for the reasons stated, and we leave the final decision to the editor.

Keep the list to two or three names: a long exclusion list reads as an attempt to steer the review rather than to avoid a conflict.
Give a factual reason, never a judgement of the person: write that a competing project exists, not that the person is hostile or unfair.
Assume the person will read what you wrote: Elsevier states that the reason is shown to an excluded reviewer who is invited anyway.; Do not use the field to exclude anyone who has criticised your work in print: disagreement in the literature is not a conflict of interest, and editors know the difference.; Leave the decision with the editor in the closing line, as with the suggestions.

What to check before you paste any of these

The templates are a starting point, not a substitute for the journal's instructions. Three checks take five minutes and prevent the two failures that actually happen: naming a conflicted candidate, and giving a number the journal did not ask for.

The number of names: MDPI journals ask for three, some Cambridge University Press titles cap it at four, Elsevier lets each journal set its own minimum, and Taylor & Francis has removed the field from its submission sites altogether. Read the Guide for Authors of the journal in front of you.
Every name against the journal's conflict policy: recent co-authors, colleagues at your own institution, supervisors, former students, and joint grant holders come off the list. The conflict of interest guide sets out the categories.; The email address of each candidate, taken from their institutional page or a recent paper rather than from a search result you did not open.
That the candidate is still active: someone who last published on the topic in 2014 is more likely to decline, which costs the editor an invitation cycle.; That the reason you wrote would still make sense to someone who has not read your paper, which is the state the editor is in when they skim the field.

Frequently asked questions

It depends on the journal. Some submission systems will not let you proceed until the field is filled in, others treat it as optional, and Taylor & Francis has removed the preferred reviewer function from its sites entirely. When the field is optional and you genuinely have no unconflicted candidate, leaving it empty is better than naming someone you cannot justify.