How many peer reviewers should I suggest?

Exactly the number the journal asks for. MDPI asks for three, some Cambridge University Press titles cap it at four, and Elsevier lets each journal set its own minimum. There is no cross-publisher standard, so the answer is always in the Guide for Authors of the specific title.

Can I suggest a reviewer I know personally?

Knowing someone is not automatically a conflict. Having co-authored with them recently, worked at the same institution, supervised them, been supervised by them or held a grant with them is. COPE uses a three-year window for recent collaborators, and several publishers apply the same figure. If a relationship would look questionable written down, name someone else.

Can I ask a journal not to send my paper to someone?

Usually yes, through an opposed or excluded reviewers field or in the cover letter. Scientific Reports accepts up to three named individuals or laboratories and states that those 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 a good argument for writing it professionally.

Does suggesting reviewers make acceptance more likely?

Not on its own, and treating it as a lever is the wrong frame. What a good list does is shorten the time to a first decision by giving the editor someone appropriate to invite immediately. What a bad list does is signal carelessness about the journal's policies before anyone has read your Methods.

How to Suggest Peer Reviewers for Your Paper

Q: Will the journal actually contact the reviewers I suggest?

Sometimes, and it is always the editor's decision. Elsevier states that the editor retains the sole right to decide whether to use them, MDPI warns that its editors will not necessarily approach them, and Scientific Reports says it is not obliged to follow the recommendations. You will not be told either way.

The submission form asks for three to five names and a reason for each. Here is why the field exists, how many names to give, and what happens to your list after you submit.

Suggesting peer reviewers is the step most authors do last, in the submission portal, at the point where the form will not let them continue. That is the wrong order, and it produces the two lists editors complain about: the four most famous people in the field, or three colleagues from down the corridor. This guide covers the mechanics, which journals ask, how many names they want, what belongs in the justification, and what the editor does with the list once you have submitted. The judgement of who qualifies is a separate question, covered in how to choose journal reviewers. If you need candidates, our free reviewer finder reads your manuscript and suggests names with the overlap stated for each one.

Why journals ask authors to name reviewers

The request is not a formality and it is not a test. Editors handle submissions well outside their own specialism, and the slowest step between a submission and a first decision is usually finding referees who are relevant, unconflicted and willing. You know your subfield better than the editor does, and you certainly know it better than a keyword search of the journal's reviewer database. Four things follow from that.

You can see the sub-specialism the editor cannot: an editor covering all of materials science cannot know who runs the specific assay in your Methods.
You shorten the invitation cycle: each invitation that is declined or ignored has to time out before the next goes out, so a list that produces one acceptance early saves weeks.
You reduce the risk of a mismatched reviewer: a referee who does not understand the method tends to ask for the wrong changes, which costs you a revision round.
The field is often mandatory: many submission systems will not accept the manuscript until it is filled in, which is why so many lists are written under time pressure at midnight.

How many names to give

There is no standard number, and guessing is what gets authors into trouble. The requirement is set by the journal, not by convention, and it varies by publisher and by title within a publisher. Read the Guide for Authors of the journal in front of you and give exactly what it asks for.

MDPI journals ask for three potential reviewers at submission.

Some Cambridge University Press titles cap the number at four, and ask that they span at least three countries.

Elsevier lets each journal set its own minimum in its Guide for Authors, and not every Elsevier journal offers the field at all.

Taylor & Francis has removed the preferred reviewer function from its submission sites entirely, so for those journals the question does not arise.

When the field is optional and you have no candidate you can justify, leaving it empty is better than filling it with a name you cannot defend.

Where the request appears in the submission

The same information turns up in up to three places, in different shapes, and knowing which one you are in front of decides how you write it. Copyable wording for all three is in the reviewer suggestion letter templates.

The structured form field: one block per candidate, with name, affiliation, institutional email, sometimes ORCID, and a free-text reason.
The cover letter: used by journals with no dedicated field, and occasionally in addition to it. Keep the two lists identical if you do both.
The opposed or excluded reviewers field: the mirror image, where you name people you would rather the editor did not approach.; A conflict of interest declaration, which is a separate obligation about your own competing interests and not about the reviewers you named.

What to write in the justification

The justification is the part that decides whether the editor uses the name. It has one job: to make it obvious in one reading that this person can judge the work and has no tie to you. Two or three sentences is the whole budget, and the pattern below fits inside it.

Name the specific overlap with your methods, not your topic. The editor knows the topic. What they cannot see is who is qualified to check the analysis.; Point at one concrete piece of the candidate's work, with a year and a claim. It shows you read them rather than searched a keyword.
State the absence of conflict explicitly: no shared publication, no shared institution, no shared funding, no supervision in either direction.; Give an institutional email address. A personal webmail address for an academic is a signal editors are trained to distrust, because that is the mechanism fake reviewer rings have used.
Avoid the two dead phrases: 'is an expert in this field' and 'is a leading authority', which carry no information the editor did not already assume.

What the editor does with your list

Understanding this stops most of the anxiety about the field. Your suggestions are an input to the editor's decision and nothing more. Elsevier states that the editor retains the sole right to decide whether to use them. MDPI warns that its editors will not necessarily approach them. Scientific Reports says it is not obliged to follow the recommendations. No publisher we could find publishes a figure for how often author suggestions are actually invited, so treat the list as a help to the editor rather than as a way of choosing your own referees.

A plausible, unconflicted list gives the editor somewhere to start on the first round of invitations.; A conflicted list is worse than no list, because it tells the editor you did not read the policy, and that colours how the rest of the submission is read.
You will never learn which of your names were invited: reviewer identity stays confidential under single-blind and double-blind review.; Editors routinely invite people you did not name, including people you have never heard of, and that is the normal outcome rather than a rejection of your list.

The mistakes that get lists discarded

Almost every discarded list fails for one of five reasons, and all five are avoidable in the ten minutes before you submit.

Colleagues at your own institution, which is excluded almost everywhere and is the most common single error.
Recent co-authors: MDPI asks that proposed referees have not published with any co-author in the last three years, and COPE applies the same window to mentors, mentees, close collaborators and joint grant holders.; Your former supervisor or your own former students, in either direction, which is a conflict regardless of how long ago it was.; Only very senior names, who decline most invitations and slow the paper down. A mix of career stages produces more acceptances.; Names with no verifiable email address, or with an address that does not match the institution given, which stalls the invitation before it starts.

Frequently asked questions

It depends on the journal. Many submission systems make the field mandatory and will not let you proceed until it is filled in, others treat it as optional, and Taylor & Francis has removed the preferred reviewer function from its sites entirely. Check the Guide for Authors before you start the submission, not while you are in it.