Q: Should I submit signatures of the co-authors in one document?
I am going to submit a manuscript to American Psychological Association (APA). Before the submission, I have to acquire signatures from co-authors on documents regarding Research Ethics and Conflict of Interest. Should I integrate their signatures into one sheet of paper?
Generally, the ethical declarations and conflict of interest statement is a single document which should be signed by all authors. Therefore you must try getting all the authors' signatures on one document. But sometimes researchers are based in different geographical locations and it may not be possible for all of them to physically sign the same document. Even if they choose to transfer the document to different locations and send it back, it may take a lot of time. Thus, most journals allow authors to submit separate copies of the declaration. However, a cover letter explaining the situation must be submitted to the journal along with the individual declarations.
You can also look up the journal website or write an email to the journal to further clarify your doubts.