ISBN is a critical part of publishing a book. The International Standard Book Number (ISBN) is a numeric book identifier that is assigned to every book to be sold commercially. And, it’s assigned to every edition or variation of a book. For example, if you will be publishing an ebook and paperback version, each one would have a different ISBN.
ISBNs are normally 10 digits or 13 digits. The 10 and 13 digit ISBN are the same except for a 3 digit prefix normally 978 or 979. ISBNs are critical because no commercial reseller will handle a book without it. ISBNs are country specific and in the United States they are issues by R. R. Bowker.
ISBNs can be costly if purchased individually but much less costly if purchased in quantity. Purchasing a single ISBN from R. R. Bowker can cost $125. You can purchase 10 for $250. I purchased 100 for $575, only $5.75 each. They are even less expensive in larger quantities.
For more information about ISBN go to https://www.myidentifiers.com/. Contact me with any questions. Thanks.