This guide outlines key points for preparing primary research manuscripts for submission to Nature Communications. The corresponding author should be familiar with the Nature journals’ editorial policies and is solely responsible for communicating with the journal and managing communication between coauthors. Before submission, the corresponding author ensures that all authors are included in the author list and agree with its order, and that they are aware the manuscript is to be submitted. For more information on editorial and authorship policies please review our Guide to Authors.Cover letterAlthough optional, the cover letter is an excellent opportunity to briefly discuss the context and importance of the submitted work and why it is appropriate for the journal. Please avoid repeating information that is already present in the abstract and introduction. The cover letter is not shared with the referees, and should be used to provide confidential information, such as conflicts of interest, and to declare any related work that is in press or submitted elsewhere.Main manuscriptThe Nature journals are flexible with regard to the format of initial submissions. Within reason, style and length will not influence consideration of a manuscript. If revisions are requested, the editor will provide detailed formatting instructions at that time. For information on length and formatting consult Nature Communications' content types.Title.If possible, this should be 15 words or fewer and should not contain technical terms, abbreviations, punctuation and active verbs.Authors.Corresponding author(s) should be identified with an asterisk.Abstract.Provide a general introduction to the topic and a brief nontechnical summary of your main results and their implication.Text length and formatting. Attention to the following details can help expedite publication if we invite a revision after external review.Articles: an abstract of approximately 150 words, unreferenced; main text of no more than 5,000 words and 10 display items (figures, tables). As a guideline, Articles allow up to 70 references. Section headings should be used and subheadings may appear in 'Results'. Avoid 'Introduction' as a heading.Methods.The Methods section appears in all online original research articles and should contain all elements necessary for interpretation and replication of the results. Methods should be written as concisely as possible and typically do not exceed 3,000 words but may be longer if necessary. We encourage you to deposit any step-by-step protocols used in your study in Protocol Exchange, an open resource maintained by NPG. These protocols are linked to the Methods section upon publication.References.These may only contain citations and should list only one publication with each number. Include the title of the cited article or dataset. Acknowledgements (optional). Keep acknowledgements brief and do not include thanks to anonymous referees or editors, or effusive comments. Grant or contribution numbers may be acknowledged. Author contributions. You must include a statement that specifies the individual contributions of each co-author. For example: "A.P.M. ‘contributed’ Y and Z; B.T.R. ‘contributed’ Y,” etc. See our authorship policies for more details.Competing financial interests.Submission of a competing financial interests statement is required for all content of the journal.Materials & Correspondence.Indicate the author(s) to whom correspondence and material requests should be addressed.Tables.Each table should be submitted as a word document and accompanied by a short title sentence describing what the table shows. Further details can be included as footnotes to the table.FiguresHigh-resolution image files are not required at initial submission, but please ensure that images are of sufficient resolution for referees to properly assess the data.