So I was posting a book today.

The ISBN on the back cover is 0329083775  (no, this is not the UPC- it is the ISBN)

It came up as not found so I was prompted to put the book's information into the system.  I entered all of that, description and image, and it was posted to my shelf.

As I was paging through it just now, I noticed that inside the book on the catalog info page is a different ISBN 0698116895

This ISBN comes up with all of the right information for the book - image, binding, page numbers, publisher, etc.

Which one is the right one?  Which one do I use? 

Hi, Jessica.

I would use the one inside the book on the catalog info page.  I say this because I have had a book that had the wrong ISBN on the back cover before (only once but still).  If 0698116895 brings up all the correct info and is on the catalog page, I would consider it the right ISBN.

Weird though.

The one on the page of with the publishing info is typically the correct one.

I would use the one on the cover of the book. If you use the one on the inside page, read through a little of the page first. I have often found a list of  ISBNs for other versions or printings there.