LCCN and the PCN program

A number printed in the book makes it easier for a library cataloger to match your book to a catalog record, and that is the whole benefit. It is worth being clear about what it isn't: having one doesn't mean the Library of Congress holds your book, it doesn't oblige any library to buy or catalog it, and it isn't copyright registration. Traditionally and hybrid published authors normally ask whether a number was requested, often as part of the publisher's Cataloging in Publication request, and record it when it arrives; a United States self-publisher who meets the program's rules normally applies through the Author Portal before the book is printed. Record the number, print it in the form the Library specifies, and send the required finished copy after publication.

A Library of Congress Control Number (LCCN) is the identifier the Library of Congress attaches to a catalog record. The Preassigned Control Number (PCN) program lets a publisher, or an author acting as self-publisher, get that number before the book is printed so it can appear on the copyright page and help libraries match the book to a record later.

The program is run through the Library's PrePub Book Link application. Publishers apply for a PCN Publisher Account and wait for approval; authors and self-publishers use a separate Author Portal and, according to the Library, can submit a request as soon as they create an account. The Library of Congress explains that the program exists to allocate control numbers in advance of publication to titles that may be added to its collections.

The LCCN printed on your copyright page and, if the Library adds the book to its collections, the number attached to its catalog record. It does not create a full catalog record on its own; that is the separate Cataloging in Publication (CIP) program. Having an LCCN does not obligate any library to buy or catalog the book.

If you are traditionally or hybrid published, ask whether the publisher has requested an LCCN and record the number when it arrives. Many publishers do this as part of their CIP request; some small presses use the PCN program on its own.

If you publish the book yourself, you can apply, with conditions. The Library's guide states that authors and self-publishers must list a U.S. place of publication on the title page or copyright page and have a U.S. address. The request must be made before publication; a PCN cannot be assigned to a book that is already out. The Library does not charge for the number, but every participant is obligated to send a copy of the finished book to the Library of Congress immediately on publication, and participants who do not can be suspended from the program. Some categories of material are out of scope; read the eligibility page before applying.

Print the number on the copyright page in the form the Library specifies: Library of Congress Control Number: followed by the number.

1. Ask the publisher for the LCCN, or find it in your PrePub Book Link account if you applied yourself.
2. Confirm the number is printed correctly on the final copyright page.
3. After publication, search the Library of Congress catalog at catalog.loc.gov (opens in a new tab) by LCCN or title to see whether a record exists. Not every book with an LCCN is added to the collection.
4. Note the LCCN on your book identity sheet alongside the ISBN and OCLC number.

An LCCN is not an ISBN, not an OCLC number, and not a copyright registration number, and the Library states that ISBNs are in no way related to LCCNs. The PCN program gives you a number; the CIP program gives you a full prepublication catalog record that includes the number. Self-published and print-on-demand titles are out of scope for CIP but may be eligible for PCN. An LCCN does not register copyright or deposit the book for copyright purposes.