The Library of Congress has a program called the Preassigned Control Number (PCN) program. Its purpose 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.
Once the book is published, these preassigned control numbers become “Library of Congress Control Numbers” or LCCNs. Strictly speaking, the LCCN is the control number for the bibliographic record entered into the Library’s database, not for the book itself.
However, libraries use the Library of Congress database, as well as other databases, to stay up-to-date on available titles, and the only way they will find your book is if it has a bibliographic record listed in the Library’s catalog.
When an LCCN is assigned to a title, the publisher adds it to the copyright page of the book. This number is then referenced in the Library of Congress database so that libraries know it exists.
It is important to note that there is no relationship between applying for an LCCN and copyright registration. They are two different programs entirely.
Unfortunately, the LCCN isn’t something that most authors even know to ask for. Yet it’s something that all libraries use. So by not requesting one, authors often miss the opportunity to have their books discovered by libraries.
Unlike ISBNs, which retailers and distributors rely upon, libraries use the LCCN to identify a title, not a format of the book. The version you apply the LCCN to should be your “best version.” Meaning that if you have a hardcover version, apply it to that. If not, apply it to your paperback. If you lack that format as well, then apply it to your eBook. As a result, you only need one LCCN as opposed to ISBNs, where you need one for each format of your title (excluding Kindle versions).
And also unlike ISBNs, LCCNs are free.
It typically takes about a week to get the number assigned, although depending on the time of year and current demand, it can take significantly less time (we’ve received them in as little as 2 days) or much longer if there’s a backlog of current applications for numbers (like around the holidays).
To apply for an LCCN, you start by creating an account at https://www.loc.gov/publish/pcn/newaccount.html and following the prompts. It can take one to two weeks before your account is issued, so make sure that you account for that in your book launch planning. It’s best to apply early and have it for when you’ll need it than to wait until the last minute and be held up by not having it.
Once your account is issued, you log in to the system and provide all of the relevant information about your book.
While we typically apply our ISBNs very early in the publishing process here at Emerald Lake Books, filing for an LCCN is done much later in the process. The reason is, for the LCCN application, you need to specify things like the approximate page count, trim size and a few other things that we may still be adjusting very late in the design stage.
Therefore, in an effort to be as accurate as possible, we wait until all edits are done and the interior design is fairly complete before filing for it.
However, since it belongs on the copyright page of the book, it’s something we must be sure is completed before we send the book off to the printers.
It’s also very important to note that once you’ve published the best version of your book, you are required to mail a copy of it to the Library of Congress for cataloging and inclusion in the Library.
Submitting your book to the Library does not guarantee it will be cataloged, but if you don’t submit it, you can be certain it won’t be!
Unfortunately, the Library doesn’t respond to status updates, so the only way to tell if your title has been accepted into the catalog is to periodically check the Library of Congress Online Catalog.