[Koha] patron accounts in a union catalogue

Howdy all, We've got some patrons who are members of multiple libraries in our Koha installation. Each library is a separate organization and therefore has different rules about overdue fines, checkout period, annual subscription fee, and so on. For this reason I suppose this means that a patron must have a separate OPAC login and patron account for each library. If s/he want to see online what books are checked out from two libraries, s/he will have to log in twice under two separate accounts, no? Thanks very much, Nelson implementing a union catalogue in Cape Town, South Africa