I have an Atlassian account and use Jira. A service provider is using Jira as well but they have their own account. I would like to get access to the details of the project (and they want to provide me that access). Do they need to add me as a new user? Or can my current Atlassian account be used to get access to the project? I'm asking this because if I need to be used as a new user to the project, there are costs involved. That does not make sense because I already have an account.