Whilst thanking you for your tip, when I started this thread it was all about Microsoft not providing this simple and common feature to home users.
This is definitely a deal breaker for me, as I was looking into Office365, and feeling that it looks a pretty good deal (especially if you factor in the 1TB storage).
Just out of interest, have you seen Microsoft's Article describing the (laborious) process of Migrating from Home to Business Edition? https://support.office.com/en-gb/article/Upgrade-Office-365-for-home-to-a-business-subscription-9322ffb8-a35d-4407-8ebe-ed6ea0859b9f
It is far from straight forward, and suggests that providing Domain Support within the Home Edition is not simply a matter of "switching" on the additional functionality (as I imagined it would be). The Home infrastructure appears to be completely separate
to the Business offering.
My guess is that providing Domain Functionality may require a complete overhaul of the Home Edition, and this is the reason Microsoft is not offering a response.
In many respects, they would be better off providing a 5-User Version of the Business platform for Home / Business use at a more reasonable charge (a bit like they have done with Windows Server Essentials).