In my experience except for an accountant account, its near impossible to have more than one type of intuit access with the same email login, there are all sorts of errors that happen when trying to add a new type of access to the same email and given that the worst problems I've had are with gopayment app, it can't be fixed by clearing cache or cookies.  I've had to create two different logins for the same email address to access gopayment app and https://merchantcenter.intuit.com/  since a client takes credit card payemnts primarily on a desktop (https://merchantcenter.intuit.com/) but also has set up an iPad with gopayment  app (same account) for new cards that a swiper can't read.  I had to create an email alias so that there were two separate email accounts goign to the same place, thankfull payment only users aren't billable in quickbooks online, or it wouldn't be possible to even manage that workaround without paying more.