Library of Congress

Preassigned Control Number Program

The Library of Congress > Preassigned Control Number Program

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. 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. Learn more about the program

Electronic PCN

ePCN Login

Cataloging in Publication Program

The Cataloging in Publication (CIP) program creates bibliographic records for forthcoming books most likely to be widely acquired by U.S. libraries. The Preassigned Control Number (PCN) program assigns a Library of Congress Control Number to titles most likely to be acquired by the Library of Congress as well as some other categories of books. The two programs are mutually exclusive.

More about the CIP program

News and Events