Invite to Join other Organization

[ToddPlank1]

A client has sent me an email invite to going their ArcGIS Online Organization.  When I attempt to use my existing ArcGIS Online account I get the message :

"The user is already associated with another organization.  You cannot join this one."

Can I not belong to more than one organization? 

Thanks

[MikeMinami]

A given username can only be associated with one organization. If you need to join another organization, you'll need to create another username.

Thanks,

Mike