ISBN is the abbreviation for International Standard Book Number which is uniquely used to identify book and allied products throughout the world. These were previously made up of only 10 digits but increased to thirteen digits from 2007. The ISBNs are necessary to identify a title or a particular edition of a title, which helps in efficient and effective marketing of books across wholesalers, libraries and distributors.

The original ten digit number had four distinct identities embedded within it. The four parts had variable lengths, with each part separated from the other by a hyphen. These parts include the country identifier, publisher identifier, title identifier and the check digit at the end of it which validates the ISBN. The ten digit ISBN number always started with the letters ISBN. The current ISBN-13 however has five distinct identities embedded in it which additionally includes a prefix of 978.

ISBNs are assigned by over 160 ISBN agencies spread throughout the world. Each agency is responsible for assigning numbers within a country or over a geographic area. Traditional book and eBook publishers, audio and video producers, software developers and those associated with any other publishing seek these ISBNs. ISBNs are also assigned to back list or forthcoming titles too. As for books, every format like hardcover, paper bound, eBook, audio or video require to have a separate ISBN. While even revised versions require having an ISBN, the ISBNs cannot be reused.

Upon the direct request of these publishers, ISBN agencies assign these numbers. ISBNs are sold in blocks of 10 or 100 and are bought by publishers depending on their future needs. It generally takes about a fortnight for processing non priority ISBN applications. There is also priority processing of 48 hours and express processing of 24 hours from the receipt of application.

A service fee is attached with all applications for ISBNs. Fee details are available with the application details. The fee for express and priority processing is obviously higher than the standard processing fee. An added advantage of having the ISBN is that it is compatible to bar code reading by bar code readers.

Allocating ISBN for books are a part of the standard publishing packages here at eBooks2go.