Handle Library of Congress prepublication records
Obtain or verify the LCCN
Ask whether the book will receive a Library of Congress Control Number through Cataloging in Publication or the Preassigned Control Number program. If it does, verify the number before the copyright page is final.
Authors often hire help with this: library or cataloging.
Why it matters
An LCCN lets a library match your book to a Library of Congress catalog record instead of starting from nothing, which removes one small piece of work from a purchase the library has already decided to make. It does not persuade anyone to buy the book, and it guarantees no acquisition by the Library of Congress or by any other library. For a self-published book aimed at libraries, it is one of the few no-cost signals that the book has been prepared with libraries in mind.
Your part
- What you do
- Verify. Someone else may do it. Inspect the result yourself.
- Who normally owns it
- Publisher. Publisher obtains; an eligible self-publisher requests a PCN directly; author verifies
- When
- Before publication and before the copyright page is finalized, typically four to six months out (Handle Library of Congress prepublication records: twelve to six months before publication, before the copyright page is final)Checked September 13, 2026 (opens in a new tab)
Your part changes with your publishing route.
How to do it
The full walkthrough
A Library of Congress Control Number (LCCN) identifies a Library of Congress catalog record. Libraries and library vendors use it to find and match records. It is printed on the copyright page. It is a control number, not a ready-made description a library can copy.
The Preassigned Control Number (PCN) program can assign an LCCN before publication, but that is not the same as full Cataloging in Publication (CIP) data. CIP creates a fuller prepublication record for eligible publishers. Neither program guarantees that the Library of Congress or any other library will acquire the book. A book gets one either as part of Cataloging in Publication (CIP) data or, for publishers not in the CIP program, through the Preassigned Control Number (PCN) program, which issues the number before publication and asks the publisher to send a copy of the finished book afterward.
Find out which route applies, then verify the number. At a publisher the LCCN usually arrives as part of the CIP application, and your job is to confirm one was requested and that the number on the copyright page proof matches the one the Library issued. If the publisher is not going through CIP, or you are the publisher, the Preassigned Control Number program is the route, and who may request it depends on who is the publisher of record on the ISBN. The Library of Congress states the program is open to United States authors and self-publishers who list a United States place of publication and have a United States address, and that books published only as ebooks are not eligible. Requests are made through the Library's PrePub Book Link system before publication. There is no fee. After publication, the program requires that a copy of the book be sent to the Library.
Rules, scope, and exclusions change over time. Confirm the current requirements on the official program page before applying.
Common mistakes
- Treating an LCCN as a finished catalog description, or as evidence that the Library of Congress will acquire the book. It is a control number for a record.
- Applying after the book is printed, when the program requires the request before publication.
- Printing the number with a typo or in the wrong format.
- Requesting a PCN for an ebook-only title, which the Library says is out of scope.
- Forgetting to send the post-publication copy that the PCN program requires.
Identifiers for Obtain or verify the LCCN
Set a status on any record and it joins this step. All book identifiers.
| My status | Identifier | Why this matters | Yours |
|---|---|---|---|
| LCCN and the PCN program A free Library of Congress catalog number you can print on the copyright page, if you request it before the book is published. | 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. | Add your LCCN | |
| Cataloging in Publication (CIP) A full Library of Congress catalog record prepared before printing and set on the copyright page, open only to publishers the Library admits. | The record is distributed to libraries before your book exists, so it shapes how the book is described in catalogs around the country, and a misspelled name or title in it is much harder to fix once the book is printed. Traditionally published authors normally read the data block when it arrives, check the spelling of their name and title, and confirm the printed copyright page matches it; a hybrid author normally has to ask first, because some hybrid publishers take part and some don't. If you publish the book yourself, this is not available to you under the program's current rules, and the Preassigned Control Number route is where to look instead. Review the data block early enough to raise a correction before the copyright page is final. | Nothing to record | |
| PrePub Book Link The Library of Congress website where prepublication catalog numbers and catalog records are requested. | This is the form, not the program, so it matters only once you have decided you need a Library of Congress Control Number. If your book has a publisher you will not use it; normally you ask which program they submitted your title through and what number or data came back. If you publish the book yourself in the United States and meet the program's rules, the Author Portal is your entrance, the Publisher Portal is not, and the request has to go in before the book is published. Keep access to the right portal and record the number issued for the book. | Nothing to record |
What done looks like
- An LCCN requested before the copyright page is finalized.
- The number printed on the copyright page exactly as issued.
- The number recorded in the Book Identity Sheet with the date issued and the program used (CIP or PCN).
- For PCN books, a note to send the required copy to the Library after publication.
Evidence. Done means someone says the work happened. Verified means you checked the confirmation, link, or public record yourself.
Ask your publisher
Copy this into an email. Replace the bracketed parts with your details.
Sources and last checked
- Official source
- Official source (opens in a new tab)
- Last checked
- September 13, 2026
- How confident we are
- Needs verification
Rules and deadlines change. We last checked this information on September 13, 2026. If you see something that needs updating, please tell us.