As of January 1, 2007, all book and book related products should carry 13-digit ISBNs. This is an industry change, and is not specific to AuthorHouse. This change is due to the volume of published books and we are excited to be a part of this growth! AuthorHouse has complied with the ISBN agency and on our authors' behalf have converted any 10-digit ISBNs to 13-digits with the prefix "978" plus the existing 10-digit ISBN. Your 10-digit ISBN is still a valid ISBN and is searchable in all AuthorHouse and industry systems. Your 13-digit ISBN is available and searchable as well. Again, AuthorHouse has accepted all responsibility for this conversion and has completed this conversion on your behalf. You need not do anything to facilitate this conversion. All documentation, such as marketing and promotional items and copyright material, displaying the 10-digit ISBN is still valid, and you should continue to use it. For more information, please visit www.ISBN.org.