The Acknowledgments page of a book is where the author gets to thank all the people who helped along the way and added their professional or moral support toward getting the book into print. Some publications, such as professional journals, don’t allow personal acknowledgments, but they’re common and expected in books.
The Acknowledgments page is the one place where you as a writer can publicly credit your editor. In many cases, it’s the one place where your editor will have verifiable proof that she worked on your manuscript, for her own CV.
Acknowledging your editor is like tipping your waiter. You don’t have to do it, but it’s polite to. You’d give your waiter a minimal tip for acceptable service; it’s polite to at least mention your editor even if you don’t feel he’s made a notable contribution to the book. You don’t have to pile on glowing praise if it’s not sincere. Just a brief “thanks to [editor] and [publisher]” is plenty. Of course, if you feel your editor helped you, developed a rapport with you, or improved your book in some way, glowing praise is always welcome—the same way that you’d tip a waiter a little extra for exceptional service.
I do a lot of work through publishers, but when I create a contract directly with an author, I have a line item indicating how my name should be spelled in the Acknowledgments. That’s the only guarantee I have that it’ll be in there; I still have no control over what the author might choose to write, nor would I want to tell a writer what to say. Firstly, they’re the writer, not me! Second and more importantly, it’s essential to keep things in perspective: My goal is to do good work for an author because I take pride in my work, not to ensure that I get a paragraph overflowing with adjectives in a published book.
What happens when the editor doesn’t get acknowledged?
Are my feelings hurt if I don’t get a mention on the Acknowledgments? Sometimes, depending on how much work I’ve put in. If it’s just been a simple proofreading job, or a once-over on a set of galleys, it’s a lot less of an issue than if I’ve been more deeply involved in the process, through more intensive copyediting or substantive revisions.
Do I take it personally? No. It isn’t personal. It’s business. It was probably either a complete oversight, or the author just didn’t feel the edits contributed that much to the finished product… and authors are not, on the whole, an ungrateful lot. If they feel that way, it’s probably because it’s the case. Catching two typos and adding a comma does not make an editor a hero.
Would I do repeat work for an author who didn’t acknowledge me? Yes. Though at that point I might bring up the subject, politely asking if the author felt I didn’t make a significant contribution to the previous book, and telling them I’d appreciate a mention if they feel I’ve contributed to this one.
It’s not worth getting upset over, but it’s not worth swallowing your perspective on, either. You’re building a professional reputation just as your author is, and put politely in those terms, they’ll usually be perfectly happy to oblige.

