Help required about how many authorisations are allowed through an Adobe id across multiple eReader apps on iPhone and iPad

[adamj77969994]

I work at the Library of the University of Manchester, book purchasing dept. We are testing logging on to multiple platforms to read eBooks. I'm using an iphone and an ipad to test this. I've got EBSCO eBooks, Adobe Digital Editions, BlueFire Reader and VLeBooks apps all downloaded on each. I have to authorise them on each device but I only have so many authorisations I can do. I'm trying to replicate it as a student to give us a better understanding about what they go through. So if there is a hitch I have to investigate why there is one

The only one I can't authorise is EBSCO eBooks as it says I have too many authorisations. Please can someone help as I thought it was a simple question for the chat support but they were useless and they sent me here. And I've no idea where to post this question and I'm pretty frustrated.