Acknowledgements are the author's thanks to the people who helped make the book. They can go either in the front matter or the back, and the Chicago Manual of Style documents both placements rather than picking one.
There is also a distinction almost no guidance mentions: there are two different kinds of acknowledgement, doing two different jobs, and they should be kept apart.
Front or Back: Both Are Correct
The Chicago Manual of Style's Q&A sets out the reasoning:
"The conventional order of elements in a book is determined by a combination of tradition and logic... In books published in English, any section that provides a key to navigating the text, starting with the table of contents, is traditionally placed in the front matter... Items that provide commentary or supporting information generally go in the back matter."
"Acknowledgments, on the other hand, may be placed either in the front matter, as a standalone item or as part of an author's preface, or in the back. When the acknowledgments go in the back, it works well to place them immediately after the final chapter, where they function as a sort of epilogue."
Yale University Press turns it into a decision rule based on length:
"Brief acknowledgments may be placed at the end of the preface, but longer acknowledgments should constitute a separate section, placed either after the preface or in the back matter."
So: a sentence or two of thanks goes at the end of your preface. Anything longer becomes its own section, front or back.
In practice, trade fiction has settled on the back, immediately after the final chapter. Academic and scholarly books more often keep them at the front. Neither is wrong.
The Two Kinds
This is the distinction worth knowing, and New Hart's Rules is the only place I found it stated clearly:
"Acknowledgements (or, in US spelling, Acknowledgments) are of two types: those recognizing the ideas, assistance, support, or inspiration of those who have helped the author to create the work; and those listing the copyright holders in material (such as quotations and extracts) reproduced in the book."
The second kind is not optional courtesy. It exists because of "the legal requirement to acknowledge the sources of reproduced material", and Hart's is specific about how it must read:
"the wording printed should be exactly as required by the copyright holder, even if this is inconsistent with style used elsewhere in the book."
That is unusual. A rights holder's required wording overrides your house style, and you may not tidy it.
Hart's recommends separating them:
"It is best to separate the two types of acknowledgement. The author's personal thanks follow the preface and are called simply 'Acknowledgements'. The names of those who hold copyright in verbal material (such as epigraphs or quotations) are listed in a separate section headed 'Copyright acknowledgements', which can appear either in the prelims or in the end matter."
Note what it names as the paradigm case for copyright acknowledgements: epigraphs. If you have quoted anyone at the head of your chapters, this section is where the permissions land.
For images, the rule differs: "Acknowledgement lines for figures, tables, and similar illustrations reproduced in the text are best listed alongside the illustration's caption rather than on a separate page, unless otherwise specified by the copyright holder."
Writing Them
Yale gives the only guidance on tone from any authority, and it is a warning:
"The best acknowledgments thank those who contributed to development of the book but are not overly effusive and do not form a mini-biography of the author's life."
No source sets a word count. What practice suggests:
- Order by contribution, not affection. Editor, agent, readers, experts, then the personal.
- Be specific about what people did. "For catching the timeline problem in chapter nine" beats "for everything".
- Name people once. A name that recurs three times reads as anxiety.
- Get the names right. This is the one page people check for themselves, and a misspelling is remembered.
- Do not apologise for omissions. A closing line about everyone you forgot draws attention to it.
One practical note from Chicago on indexing: where a book has an index, "it's common to allow a certain number of 'vanity' entries, if there is room", meaning names from the acknowledgements can appear in it.
Spelling
Acknowledgements in British usage, Acknowledgments in American. New Hart's Rules states it directly: "Acknowledgements (or, in US spelling, Acknowledgments)". Chicago and Yale both use the shorter American form.
Match your market, and be consistent with the rest of the book's spelling.
What Deckle Does
Deckle has an Acknowledgments document type, using the American spelling, and it is filed under the Back Matter menu alongside About the Author, Also by the Author, Coming Next, Book Club Questions and Glossary. It starts with the placeholder "Begin your acknowledgments here."
That placement matches Chicago's current recommendation and trade fiction practice, but the menu grouping is a convenience rather than an instruction. Export order follows Binder order, so if you want them at the front, create the document and drag it up into the front matter. Both work.
The consequence of where you put it is the page numbering: front matter takes roman numerals, back matter continues the text's arabic sequence. So the same document numbers differently depending on position, which is correct in both cases and explained in how to number the pages of a book.
If you need a separate "Copyright acknowledgements" section as New Hart's Rules recommends, create a second ordinary document for it rather than mixing the two kinds into one page.
For the neighbouring elements, see dedication vs epigraph vs acknowledgements and what is back matter in a book.
Common Mistakes
- Assuming there is one correct placement. Chicago documents both front and back.
- Mixing personal thanks with copyright credits. New Hart's Rules advises separating them.
- Editing a rights holder's required wording. It overrides your house style.
- Writing a memoir. Yale warns against a "mini-biography of the author's life".
- Misspelling a name. The one page those people will read closely.
- Using the wrong spelling for your market. Acknowledgements in the UK, Acknowledgments in the US.
FAQ
Q: Front or back? A: Both are correct. Yale suggests deciding by length; trade fiction usually puts them at the back.
Q: How long should they be? A: No authority sets a limit. Yale warns against effusiveness and autobiography.
Q: Do I have to thank my publisher? A: No. Nothing here is obligatory except copyright acknowledgements, which are a legal requirement.
Q: Where do image credits go? A: Alongside the caption, not in the acknowledgements, unless the rights holder requires otherwise.
Q: Acknowledgements or Acknowledgments? A: The first is British, the second American. Deckle uses the American spelling.