Library of Congress Control Numbers: Do Self-Publishers Need Them?

The Library of Congress Control Number

The Library of Congress Control Number, or LCCN, is an often overlooked detail in independent publishing. This blog post will explain what it is, how to use it, and why you need one (or don’t).

(Note: this post applies to books published in the U.S. Other countries will have their own requirements.)


First, what is it?

Here’s the description directly from the Library of Congress website:

A Library of Congress catalog control number is a unique identification number that the Library of Congress assigns to the catalog record created for each book in its cataloged collections. Librarians use it to locate a specific Library of Congress catalog record in the national databases and to order catalog cards from the Library of Congress or from commercial suppliers. (source:

In other words, having an LCCN assigned to a book makes it much easier for libraries to acquire it. If selling to libraries is a major part of your marketing plan, it might be worthwhile to obtain this cataloging number.

But wait, there’s a catch.

The LCCN (and corresponding Catalog in Publication (CIP) Program) is largely reserved for large publishers or pre-approved independent presses. To be eligible to apply for the CIP program, you must meet these requirements:

Only U.S. publishers who publish titles that are likely to be widely acquired by U.S. libraries are eligible to participate in the CIP program.

Every publisher/imprint must have already published a minimum of three titles by three different authors. All three titles must have been widely acquired by U.S. libraries.

(The full list of requirements can be found here:


Since most self-publishers and small presses do not meet these requirements (at least with their first book), there is a second option available: the PCN, or Preassigned Control Number program.

The purpose of the Preassigned Control Number (PCN) program is to enable the Library of Congress to assign control numbers in advance of publication to those titles that may be added to the Library’s collections. The publisher prints the control number in the book and thereby facilitates cataloging and other book processing activities. The PCN links the book to any record which the Library of Congress, other libraries, bibliographic utilities, or book vendors may create. (source:

Just like the LCCN has a CIP (cataloging in publication), the PCN has what’s called P-CIP. This is simply the cataloging data for the PCN.

Applying for a PCN is a two-step process. To read the application steps and to submit your forms, visit

When you receive your PCN, the Library of Congress asks that you include it in your copyright page in the following format:

Library of Congress Control Number: 2007012345

(The first four numbers will correspond to the year you applied (in the example above it is 2007). Even if your book is published the following year, do not change this number. It must remain exactly as received from the Library of Congress.)

Is it worth the time and effort?

As the application for a PCN is a lengthy process, you might be wondering if it’s worth all the work and wait.

In his blog,, Joel Friedlander offers the following insight:

“If you anticipate making any appreciable sale to libraries, it’s probably well worthwhile to get P-CIP. Having this cataloging information simply makes librarians’ jobs that much easier, reducing their resistance just a bit to acquiring your book for their collection.”

“Particularly if you publish reference books, histories, books about local events that would be of interest to libraries in your region, travel books, directories, how-to books on popular topics, or similar books, you could well have a good sized market with the thousands of libraries, both public and private, throughout the country.”

Read more here.

LCCN / PCN Conclusion

Think about your book marketing plan and target audience. Are libraries a major part of your ideal purchasers? If the answer is yes, then it’s worth your while to obtain a PCN or LCCN. However, if the library market is not part of your marketing plan, then perhaps you can ignore the entire PCN process. If most of your book sales will be direct-to-reader via online retailers like Amazon, then you don’t really need to go through this extra process.

Also, keep in mind that just because your book does have a PCN, this does not mean that libraries will automatically accept your book. With such a large amount of published books, libraries unfortunately cannot accept every single book. But, you never know until you try!

If you’re curious to learn more about the PCN and the data block for your copyright page, visit Joel Friedlander’s post. He offers valuable advice, a breakdown of the various parts of the data block, and also resources and vendors that prepare P-CIP data blocks for small presses and self-publishers.

Another great article about the LCCN and PCN can be found at

Photo by Thomas Kelley on Unsplash

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