What Authors Need to Know About ISBNs (Before You Publish)

📘 Smart Publishing Impact Series – Episode 45

ISBNs are not a sexy topic—but they are one of the most misunderstood parts of publishing.

I get questions about ISBNs from first-time authors and seasoned authors all the time. And most of the confusion comes from one thing: authors don’t realize they’re making a permanent publishing decision when they choose how to handle their ISBNs.

So let’s slow this down, simplify it, and walk through what actually matters—so you can make the right choice before you publish.

First—What Is an ISBN?

ISBN stands for International Standard Book Number.

It’s a 13-digit unique identifier used worldwide to track books in:

• retail systems

• libraries

• distribution databases

• inventory ordering

You’ll usually find it:

• on the barcode on the back of a printed book

• sometimes on the copyright page

An ISBN identifies both the book and the publisher. And no two books—or formats—share the same ISBN.

That means:

• Paperback = one ISBN

• Hardcover = one ISBN

• (Optional) Ebook = one ISBN

Each format must be distinguishable for ordering and tracking purposes.

Do All Books Need an ISBN?

No.

And this is where authors often overthink.

If you are publishing:

• Exclusively on Amazon

• Selling primarily through Amazon

• Not actively pitching bookstores or libraries

👉 You do not need to purchase your own ISBN.

Amazon provides free ISBNs for paperback and hardcover when you publish through KDP. Kindle ebooks don’t require an ISBN at all.

However—this choice comes with limitations.

Amazon ISBN vs. Your Own ISBN

If you use Amazon’s free ISBN:

• Your book is tied to Amazon’s system

• You cannot use that ISBN for expanded retail distribution

That’s not a bad thing—it’s just a strategic choice.

Here’s the reality most authors need to hear:

Over 60% of books sold worldwide are sold on Amazon.
Barnes & Noble—both online and in physical stores—holds about 18% of the market.

If you are not planning to actively:

• pitch bookstores

• work with libraries

• pursue wholesale distribution

…then buying ISBNs often makes no financial or strategic sense.

When You Should Buy Your Own ISBNs

Purchasing your own ISBNs makes sense if:

• you want full distribution control

• you plan to distribute beyond Amazon

• you are pitching libraries or retailers

In the United States, Bowker is the official ISBN agency.
(If you’re buying ISBNs elsewhere—you’re likely being scammed.)

👉 Buy directly from Bowker (myidentifiers.com).

ISBN Pricing: Why Bulk Matters

ISBN pricing is where authors often get burned.

Current pricing (at time of recording):

• 1 ISBN: $125

• 10 ISBNs: $295 (≈ $29.50 each)

That’s a massive difference.

If you plan to:

• write more than one book

• publish in multiple formats

• build a long-term author career

Buying in bulk upfront can save you thousands over time.

A Critical Warning: ISBNs Are Permanent

Once your book is published:

• your ISBN is locked

• it cannot be swapped out

• it cannot be removed later

To change it, you would need to:

• take the book down

• potentially alter metadata

• republish as a new edition

So before you publish, be absolutely clear on:

• your distribution strategy

• where you plan to sell

• how much marketing effort you’re realistically willing to put in

ISBN decisions should be intentional—not emotional.

ASIN vs. ISBN (Don’t Confuse These)

This is another common point of confusion.

• ISBN = international identifier for books

• ASIN = Amazon’s internal product ID

An ASIN is not an ISBN.

Amazon assigns an ASIN to every product in its system—including books. Even if you purchase your own ISBN, Amazon will still use an ASIN internally.

They serve different purposes.

A Reality Check on Bookstores & Libraries

Many authors dream of seeing their book on bookstore shelves—and that’s understandable.

But here’s the truth:

• bookstores have limited shelf space

• they prioritize fiction, cookbooks, pop culture, and celebrity memoirs

• business nonfiction performs far better online than in-store

If your book is:

• business

• leadership

• self-help

• professional nonfiction

Your audience is almost certainly buying on Amazon.

Unless you want a part-time job pitching retailers, publishing exclusively on Amazon is often the smartest move.

Final Thoughts

ISBNs are not about prestige—they’re about strategy.

There is no “right” or “wrong” choice—only the choice that aligns with:

• your goals

• your bandwidth

• your distribution plan

If Amazon is your primary platform, use the free ISBN and move forward confidently.
If you want full publishing control and wider distribution, invest wisely and buy in bulk.

Just make the decision before you publish—because once your ISBN is assigned, it’s set in stone.

And as always—

Keep writing your story, because the world needs your voice.
—Renee