Sometimes before you do something you will regret, you know it’s a bad idea but you go down that path anyway. You have a feeling in the pit of your stomach that it’s the wrong thing to do, but for one reason or another, all the facts in front of you mean you keep on going.
That’s how you should feel if you are considering having multiple Office 365 tenants for your organization. The default position is use a single Office 365 tenant for your company if you can.
If that’s all it takes to convince you, then feel free to stop reading here. I know you want to find out why, though. If you do want to find out why, or worse – you actually want to do it, then keep reading.
Important questions you need to ask
The first question you should ask yourself, and everyone else should be asking you – is why? Why does your organization need multiple Office 365 tenants? Maybe you do have some solid reasons for why it is desirable – if so, then it’s important to make sure you understand what they are, and what the supporting evidence is.
Secondly, you need to work out how you will do it. If you run a single Active Directory, or even multiple AD forests, then it’s not going to be as simple as just adding multiple Office 365 tenants into Azure AD connect.
Thirdly you understand what it will be like to live with. How will people across the multiple tenancies share and distribute information? What will the user experience be like? What will it be like to manage in the longer term?
Common reasons for multiple tenancies
Whilst it is easy to dismiss the idea of using multiple Office 365 tenants, sometimes it can be felt there is not another option. Some of the reasons I’ve heard do have solid underpinnings:
· We have a strategy to move everything to Office 365, but data must be resident in certain geographies.
· We must be able to allow full autonomy of administrative control for divisions / operating units within the organization.
· A variation of the above, we currently run separate environments for each division / operating unit for legal reasons and want to continue with that model.
· We must avoid latency issues with particular Office 365 workloads, like Skype for Business and SharePoint Online.
Each of these may have alternative solutions to solve the problem in the short and long term, but mean that you will need to consider how you’ll achieve the goal and what the end result will be like.