How to tactfully refuse to be listed as a co-author I was involved with a research project with a group of people. Eventually, a paper was written and was accepted by a journal. I did not agree with the content of the paper and I didn't want to be listed as a co-author, but I did not want to create bad feelings between myself and the rest of the group.
The journal has a policy where every co-author has to turn in a signed agreement that they substantially contributed to the work. I refused to sign that document I thought that by refusing to sign that document, I would be left off the co-authors list.
However, the journal went ahead and included me without me signing the form. It is not going to ruin my reputation to have my name on this paper, but I didn't want my name on the paper and I am just wondering what I should have done differently to resolve this problem.
Well, there were a lot of mistaken decisions here, including by the journal to list your name.
To answer your title question, you should have, before the paper was submitted, told the group you didn't want to be involved, whether you said something like &quot;I disagree with the conclusions of this paper, and don't want to be an author,&quot; or a white lie like &quot;I don't feel I contributed enough to be an author.&quot;

You can also offer to be happy to be acknowledged; I find this is an option for authors who do not wish to hide an unwilling collaborator's contribution without making them co-responsible for the publication. This can soften the blow of disagreement without requiring to lie. - Captain Emacs

Upon getting the form, you shouldn't have silently declined, you should have talked with the other authors and informed the journal you were included accidentally. With everyone's consent, they would have taken  you off.