Editio Self-Publishing discussion

I was wondering if anyone knows the absolute rule on ISBNs for ebooks. Everything I've been reading is all very contradictory and there is no real information on the actual ISBN UK website. If your book is available in for example PDF, Mobi and Epub do all three versions need different ISBNs? And if anyone knows the answer could they point me to the up-to-date link/article that states the rule absolutely with no doubt or confusion as to what the answer is.

My understanding is that you are encouraged to have a different isbn for each format - ePub mobi and paperback. I found the whole isbn process rather slow. Make sure to sign up for pubweb as soon as you have your isbns. The system is like something from the 80's. You fill out a form online and it takes about 4 weeks for the details to be processed.

Just published my first book at Smashwords and Amazon. Smashwords issued a free ISBN, so can I use that at Amazon? Has anyone done this? My book is only available online.

Good question @Elizabeth. I'm wondering the same thing too but there's so much conflicting info. out there.

I don't think that you can. The ISBN means that Smashwords is the publisher of record. But the good news you don't need an isbn to publish on kdp.

Ok, I think I'll leave it off the Kindle edition then. I realise that it's not necessary, but it's the first one I've ever had and just wanted to use it!

Elizabeth wrote: "Just published my first book at Smashwords and Amazon. Smashwords issued a free ISBN, so can I use that at Amazon? Has anyone done this? My book is only available online."

Elizabeth,
I followed the same path; published an ebook on Smashwords and recieved a free ISBN. Before this though I published same book on Amazon without ISBN. Unless your ebook is also available in print, I don't believe an ISBN is absolutely necessary on Amazon. Don't quote me though.

Thanks Scotty, I'll leave it off though, I suppose it seems a bit unfair to get one free from Smashwords and then use it elsewhere.