Researching a book can get out of hand fast.

You start by looking up one thing you need for a chapter, and pretty soon you’ve got interview notes, charts, timelines, photos, maps, source lists, recommended reading, and some odd little detail you spent forty minutes finding even though it has no business sitting in the middle of chapter seven.

The annoying part is that some of that material is useful.

Not all of it. Some of it probably needs to be cut and left alone. But sometimes you really do have extra information that a certain kind of reader would appreciate, even though putting it in the main chapter would slow everything down.

An appendix gives you a place for the supporting material without forcing every reader to deal with it at the exact moment they’re trying to move through the book.

I’ve been writing and formatting books for over a decade now, and when I created Atticus, I had to dig into all the tiny parts of a book that most authors ignore until they’re formatting. Title pages, copyright pages, front matter, back matter, chapter structure, appendices… all the stuff that seems simple until you have to decide what goes where.

An appendix is one of the easier pieces once you understand the purpose. It’s not a junk drawer for everything you couldn’t fit. It’s not required just because you did research. And it’s not something every book needs.

A nonfiction book might use an appendix for data, transcripts, or research material. A biography might use one for letters, photos, or timelines. A fantasy novel might use one for maps, family trees, or language notes. A simple novel probably won’t need one at all.

The real question is whether the material helps the reader without belonging in the main text. If it does, an appendix can be the cleanest place to put it.

This is only one of many posts that discuss all the different components and parts that go into creating a book. I recommend further reading!

Why Should You Trust Me?

I've actually been writing and formatting books for a long time. Over 10 years so far, and counting.

But that's not the real reason, because there are plenty of authors who have lots of experience, but know next to nothing about the different parts of a book, or book formatting in general.

The real reason you should trust me is because I actually created my own formatting software that solved all my problems. I called it Atticus.

But this isn't meant to be a sales pitch. I just want to make sure it's clear that I know what I'm talking about. The amount of research that went into not only formatting my own books, but also creating a formatting software is huge.

I researched everything, which led me to learn all about every. single. part. of. a. book. And there were a lot more than I realized.

And of course, that includes Appendices.

So if all that makes sense, hopefully you'll come along with me as show you everything I've learned.

What is an Appendix in a Book?

You can think of the appendix as a place for “bonus material” that doesn't make it into the main body of the book. If including the information in the book will interrupt the flow of the chapter, you can put it in the appendix (appendices, for more than one).

This information should still be at least tangentially relevant to the subject matter, but maybe just not important enough to include in the body.

Where Does the Appendix Go?

Appendices are found in the back matter of books. It should come after the epilogue, afterword, and acknowledgments but before the glossary, endnotes, bibliography, index, and biographical note (in that order).

In the images below, I show how simple it is to add multiple appendices to your book with Atticus. The drag-and-drop menu allows you to select what type of section you would like to add and exactly where you would like to put it. You can also drag sections to different positions later, if you wish. For this one, I simply used a chapter section because appendices should be formatted like chapters. (More on this later.)

What Books Have Appendices?

As you can probably guess, your fiction book won't necessarily need an appendix. If it's a historical fiction book, you could put an appendix in, detailing interesting things you came across in your research. This is a personal preference. If your readers will appreciate it, then it could be worth the bit of extra effort to add a book appendix.

Nonfiction books most commonly have appendices. Many academic textbooks have supplementary information in one or more appendices. But you'll also see them in technical books, biographies, or any type of nonfiction for which you did significant research that might be of use to your readers.

Do You Need an Appendix?

If you ever had to write a research paper for school, you may remember having to add an appendix. Maybe this was a requirement to meet to get a passing grade on your essay. While the purpose of an appendix in book writing is the same, there is no requirement that you put one in. By definition, the appendix contains extra information that isn't directly relevant to your argument or the theme of your book.

So how do you know if you really need one?

Here are some guidelines you can use to determine if your book needs one or more appendices:

• There is a subject you can expand on that doesn't need to be in the body text of the book but may interest readers.
• You would like to provide additional information about your sources or research methods.
• You have interview transcripts, photos, correspondence, graphs, tables, or other supplementary material to provide.
• You would like to recommend further reading.

What Goes in an Appendix?

The information in an appendix is typically too long, complex, or detailed for mention in the body of the work. If what you want to reference is short enough for a footnote, then you don't need to put it into an appendix.

However, if it seems like a diatribe or something the reader doesn't need to understand the message or overall information you're trying to get across, it should go in the appendix.

The specifics of this information will depend entirely on the type of book. Technically, if your book is nonfiction, it can have an appendix. That doesn't necessarily mean that it should, though. It's best to look at similar books to see if they have appendices. If they do, you may want to include one or more in the back of your book.

Referencing Your Appendix

To make things as easy as possible for your reader, it's a good idea to reference your appendix correctly in the main text of your work. To do this, don't use page numbers. Instead, reference the title of the appendix. Here are a couple of examples:

• Correct: (See Appendix A for more details)
• Incorrect: (See page 443 for more details)

If you only have one appendix, you can simply say “See Appendix for more details.” You don't have to reference each appendix section in the body paragraphs. You can also reference them in footnotes, if appropriate.

If you have multiple appendices, you'll want to put them in the same order you referenced them in your main text. And to make it perfectly clear to your reader, use numbers or letters and titles to signify each appendix. Here are some examples:

• Appendix A: Interview Transcripts
• Appendix B: Photographs
• Appendix C: Family Tree

You can also use numbers instead of letters before your appendix label:

• Appendix 1: Recommended Reading
• Appendix 2: Charts
• Appendix 3: Polling Questions

Should Your Appendix Be In Your Table of Contents?

Your separate appendices should be clearly labeled in your Table of Contents at the front of your book. This will make things easier on your readers, allowing them to quickly see on what page number each appendix starts. Be sure to include the appropriate appendix title here, as well.

Formatting Your Appendix

There aren’t any strict rules for formatting an appendix. As a rule of thumb, you’ll want to keep it in the same format as the rest of your book. This means using the same font, heading types, margins, and spacing. 

You can reference whatever style manual you prefer for more information on formatting your appendix. For example, the Chicago Manual of Style allows for either letters or numbers. APA style suggests that you only use numbers for multiple appendices. Whichever you choose, just keep it consistent. 

Appendix Headings

Appendix headings should be formatted just like chapter headings in your book. You can also include subheadings if you need to. And just like chapters, each new appendix should start on its own page.

In the image below, you can see how easy it is to format your appendix in the Atticus writing tool. From naming the appendix to adding headings and inserting information, Atticus makes things as easy as possible — even for those who’ve never used a dedicated writing tool like this before. 

When it comes to labeling figures and tables, it's also good to reference your preferred style book for guidance. Most style books will state that you use the same number or letter of the appendix title. Under APA format, you would label those figures in Appendix A like so: Table A1, Table A2, Figure A1, Figure A2, etc.

Appendix vs Reference List

It's important to note the difference between an appendix and a reference list. In most academic writing, a reference list, otherwise known as an annotated bibliography, is a requirement. An appendix is not always required. (Of course, college students should check with their professors).

In book writing, it will be up to the author to decide whether to include an appendix. Most nonfiction books should have a bibliography, though.

Book Appendix Examples

Stephen King's 1981 nonfiction overview of the horror genre, Danse Macabre, has two appendices. Since he discusses horror books and movies in the book, he has an appendix for each, labeled Appendix 1 for the books and Appendix 2 for the movies.

These are simple appendices, listing the books and movies he mentioned in the order in which they appear in the book. This is an excellent example of an appendix because it provides quick and easy reference for each book. However, he also has an Index, allowing readers to look up each mention by page, so they can go back and read over what King said about each piece of content.

Unless you're delving into a particularly complex topic, you won't need to include images or figures. Again, it's up to you what to include.

An appendix can be as simple as this:

Appendix A: Recommended Reading

• Book Title, Author Name
• Book Title, Author Name
• Book Title, Author Name

Below is an example of an appendix made in Atticus. With the preview feature, you can choose different ready-made formatting options to see how your book will look on over a dozen different devices. You can also make changes here to ensure your appendix looks exactly how you want it — and you don’t have to spend more than a few minutes getting it there. 

For more appendix examples, a simple Google image search or a trip to the local library can yield more than enough appendices. You may even have books with appendices on your bookshelf now!

Final Thoughts on Writing an Appendix

Most books don’t need an appendix.

If you’re writing a straightforward novel, you can probably skip it and move on with your life. No one is going to reach the end of your thriller and wonder where the bonus charts went.

But if you have material that helps the right reader, and it would bog down the main text, an appendix can make sense.

That might be interview transcripts. Extra research. Maps. A family tree. A list of recommended reading. Technical details. Charts. Photos. Source material. Anything that adds value for the person who wants it, without forcing everyone else to stop and read it in the middle of the book.

The key is to be honest about whether it’s useful or whether you just don’t want to cut it.

If the reader needs it to understand the book, it probably belongs in the main text. If it only supports the book, adds context, or gives curious readers somewhere to go after the chapter, the appendix may be the right place.

Label it clearly. Keep the formatting consistent. Reference it by title or letter when you need to.

And don’t make it harder than it needs to be.