ISBN

We buy the International Standard Book Number so that it can be recognized by any database anywhere in the world. They are allocated to publishers, and identifiable as such, so they cannot be transferred between individuals/companies or titles. They are 13 digits – prior to 2007 they were 10 digits, so for some books we have two. A separate ISBN is not necessary for Amazon, but it is for most other online outlets. You can find the paperback ISBN in the top left-hand corner of your Book Details page; it is also listed at the bottom of your Book Details page under META DATA, as is the ebook ISBN.

We sometimes re-package titles, particularly if an author has published several with us, they're going well, and we want a more consistent approach for them. In which case-  

The ISBN Agency says publishers need to assign a new ISBN if

• Title is changed
• Sub title is changed
• New format is produced
• ​Cover is changed and the previous cover edition is still available. 
• Title is moved into different imprint
• There is more than one volume in a series, need separate ISBN for each volume and an extra for the series as a whole
• It would be worth someone buying the revised edition, having already bought the previous one
• The supply chain needs to differentiate the new edition from a previous one 
• It is necessary to be able to specify this new edition with x, y, z changes rather than that one without
• The publisher markets the book as a different edition number 

And publishers don’t need to assign new ISBN if

• Cover changed and no other editions with a different cover are available to readers
• Price changed
• misprints and typos corrected