How to Get a Library of Congress Control Number (LCCN) — and Why It Matters
A short guide for indie authors publishing print books in the U.S.
If you're publishing a paperback or hardcover in the U.S., you may be eligible for a Library of Congress Control Number (LCCN). This isn't the same as an ISBN, and it doesn't guarantee your book will end up in the Library of Congress. But it does make your book easier to catalog, more appealing to libraries, and more professionally presented. Here's how it works.
What Is an LCCN?
A Library of Congress Control Number (LCCN) is a unique identifier created by the Library of Congress to help libraries and booksellers catalog books before they’re published. It’s not required for publication—but having one improves how your book is classified in databases and library systems.
It’s particularly useful if you’re hoping your book will be acquired by libraries, schools, or academic institutions. It’s also one of those small, professional touches that can quietly raise the credibility of your print edition.
Why Should Indie Authors Get One?
Easier access to libraries: An LCCN helps libraries catalog your book correctly.
Academic and professional credibility: Schools and libraries are more likely to consider books with LCCNs.
Retailer and wholesaler readiness: Some distributors and bookstores prefer books with LCCNs for cataloging purposes. Some distributors and bookstores prefer books with LCCNs for cataloging purposes.
Note: An LCCN does not guarantee your book will be housed by the Library of Congress. It simply creates a record to help libraries classify it.Having an LCCN does not mean the Library of Congress will acquire or shelve your book. It simply creates a catalog record.
Who Can Apply?
You can apply if:
You're a U.S.-based self-publisher or small press
You're publishing a physical book (paperback or hardcover)
You cannot apply if:
You're publishing only in ebook format
You live outside the U.S. without a U.S.-based publishing address
How to Apply for an LCCN
You must apply through the Preassigned Control Number (PCN) Program before your book is published.
Go to the PCN Program page:
https://loc.gov/publish/pcn/Create an account and complete the publisher application. Approval usually takes a few business days.
Once approved, log in and apply for a new LCCN by submitting your book’s:
Title
Author name
Publisher name (your name or imprint)
ISBN
Anticipated publication date
Within 1–2 weeks, you’ll receive your LCCN by email.
You’ll then need to place it on your copyright page before printing your book.
After You Receive Your LCCN
Add it to your copyright page (usually below the ISBN)
Print and distribute your book
If requested, send a copy of the finished book to the Library of Congress (they don’t always ask, but sometimes they do)
You can find the full LCCN submission requirements here:
https://www.loc.gov/publish/pcn/about/index.html
Notes for International Authors
While this article focuses on the U.S. Library of Congress Control Number system, other countries have similar cataloging and legal deposit systems:
United Kingdom: The British Library operates under a legal deposit system that requires publishers to submit a copy of every printed publication. This allows for cataloging and accessibility through national library networks. More info
Germany: The Deutsche Nationalbibliothek (German National Library) requires submission of print materials for cataloging and preservation. Every book receives a unique identifier in the national bibliography. More info
Italy: The Biblioteca Nazionale Centrale in Rome and Florence oversees a legal deposit system similar to those in the UK and Germany. While there is no direct equivalent to the LCCN, legal deposit ensures national cataloging. More info
These systems don’t offer the same pre-publication identifiers as the LCCN, but they serve a similar function in helping preserve and catalog a nation's publishing output.
Final Notes
LCCNs are free and relatively quick to obtain—but only for U.S.-based publishers of print books.
This is not the same as applying for CIP data (Cataloging-in-Publication), which is more complex and generally reserved for traditional publishers or academic presses.
If you're planning to market your book to schools, libraries, or educational wholesalers, it's a good idea to get an LCCN.
LCCNs won’t sell books—but they can open doors in library and academic markets, and they’re a simple way to make your book more catalog-friendly. If you’re publishing a print edition in the U.S., take a few minutes and apply. In future posts, we’ll talk more about CIP data, library distribution, and what it really takes to get your book onto library shelves.