Understanding Tenants, Subscriptions, Regions and Geographies in Azure

If you are getting started working with Azure you might come across a few key terms that it’s important to have a good understanding of. In this post I’m going to cover what I think are four of the key ones.


A Tenant, as it relates to Azure, refers to a single instance of Azure Active Directory, or, as it is often called “Azure AD”. Azure AD is a key piece of Microsoft’s cloud platform as it provides a single place to manage users, groups and the permissions they hold in relation to applications published in Azure AD.

Key Microsoft applications that Azure AD provides access to include Office 365, Dynamics 365 and Azure. Yes, you read that right, Azure is treated as an ‘application’. You can also use Azure AD to control access to many other third-party applications such as Salesforce and even the AWS admin console. As an application developer you can register your own applications in Azure AD for the purpose of allowing users access.

Azure AD Tenants are globally unique and are scoped using a domain that ends with ‘onmicrosoft.com’ (i.e. myazuread.onmicrosoft.com) and each has a ‘Tenant ID’ in the form of an UUID/GUID. Some customers choose to connect their internal Active Directory environment to Azure AD to allow single or same sign-on for their staff and will also use a custom domain instead of the default ‘onmicrosoft.com’.

When you access the Azure Portal, or leverage one of the command-line tools to manage Azure resources in a Subscription, you will always be authenticated at some point via the Azure AD Tenant associated with the Subscription you want to access. The actions you can take will depend on the Role you have been assigned in the target Subscription.

Finally, Azure AD Tenants can be associated with multiple Subscriptions (typically in larger organisations), but a Subscription can only ever be associated with a single Azure AD Tenant at any time.

Dev Tip: if you want to develop an application that uses Azure AD but don’t have permissions to register applications in your company’s Azure AD Tenant (or you want a ‘developer’ Azure AD Tenant) you can choose to create a new Azure AD Tenant in the Azure Portal. Make sure in your application that you can easily change Azure AD Tenant details to allow you to redeploy as required. Azure AD has a free tier that should be suitable for most development purposes.

IT Pro Tip: you can change the display name for your Tenant – something I strongly recommend, particularly as Azure AD B2B will mean others will see your Directory name if they are invited and may be confused if the display name is something unclear. Note that you are *not* able to change the default onmicrosoft.com domain.


A Subscription in Azure is a logical container into which any number of resources (Virtual Machines, Web Apps, Storage Accounts, etc) can be deployed. It can also be used for coarse-grained access control to these resources, though the correct approach these days is to leverage Role Based Access Control (RBAC) or Management Groups. All incurred costs of the resources contained in the Subscription will also roll-up at this level (see a sample below).

Subscription costs view

As noted above, a Subscription is only ever associated with a single Azure AD Tenant at any time, though it is possible to grant users outside of this Tenant access. You can also choose to change the Azure AD Tenant for a Subscription. This feature is useful if you wish to transfer, say, a Pay-As-You-Go (PAYG) Subscription into an existing Enterprise Enrolment. Subscriptions have both a display name (which you can change) and a Subscription ID (UUID/GUID) which you can’t change.

Subscriptions are not tied to an Azure Region and as a result can contain resources from any number of Regions. This doesn’t mean that you will have access to all Regions, as some Geographies and Regions are restricted from use – we’ll talk more about this next.

Resources contained in a Subscription, but deployed to different Regions will still incur cross-Region costs (where applicable) for the resource.

People sometimes use the word ‘Tenant’ instead of ‘Subscription’ or vice-versa. Hopefully you can now see what the difference is between the two.

Regions and Geographies

Azure differs from the other major cloud providers in its approach to providing services close to the customer. As a result, and at time of writing (August 2018), Azure offers 42 operational Regions with 12 more announced or under development.

A Region is a grouping of data centres that together form a deployment location for workloads. Apart from geo-deployed services like Azure AD or Azure Traffic Manager you will always be asked what Region you wish to deploy a workload to.

Regions are named based on a general geography rather than after exactly where the data centres are. So, for example, in Australia we have four Regions – Australia East, Australia Southeast, Australia Central 1 and Australia Central 2.

A Geography, as it relates to Azure, can be used to describe a specific market – typically a country (Australia), though sometimes a geographic region (Asia, Europe). Normally within a Geography you will find two Regions which will be paired to provide customers with high availability options. Can anyone spot the one Region that doesn’t have its pair in the same Geography?

There are a few special Regions that aren’t open to everyone – US Government Regions, the entire German Geography and China. In Australia, in order to access Australia Central 1 and 2 you must undergo a white listing process to gain access.

When you replicate data or services between Regions you will pay an increased charge for either data transfer between Regions and / or duplicated hosting costs in the secondary Region. Some services such as Azure Storage and Azure SQL Database provide geo-redundant options where you pay an incremental cost to have your data replicated to the secondary Region. In other cases you will need to design your own replication approach based on your application and its hosting infrastructure.

Once you have deployed a service to a Region you are unable to move it – you have to re-provision it if you need the primary location to be somewhere else.

As a final note, while there is a Regional availability model (replication of services between Regions), Microsoft has also introduced the concept of Availability Zones. Availability Zones are still being rolled out globally, and are more than just a logical overlay over Regions. There is a great infographic on the Azure Resiliency website that covers how Regions and Availability Zones work and the value they provide.

So there we have it, a quick overview of some of the key terms you should be familiar with when getting started with Azure. As always, if anything’s unclear or you have any questions feel free to drop a comment below.


22 thoughts on “Understanding Tenants, Subscriptions, Regions and Geographies in Azure

  1. I was having a hard time understanding the difference between a Tenant and Subscription and how the Azure AD Domain fits in but your article did a great job at explaining it. Thank you for the blog post!

  2. Can an organization which has a tenant with all infrastructure based in one region (Western Europe) create new VMs in another region (Northern Europe), which is cheaper! I don’t want to duplicate data just create new Vm’s in this region. Can I also transfer the current VM’s to a different region that is cheaper?

    1. Matt – generally speaking a Subscription can use any Region. There are a few exceptions such as Azure in China and the Gov Cloud Regions in North America, but a new Subscription will have access to the majority of Regions that are available.

      Moving VMs between Regions is possible, but it’s not a ‘click button’ experience. You would either need to use Azure Site Recovery (ASR) to duplicate to the second Region or manually move the disks between Regions and create a new VM and attach them (which is effectively what ASR is automating).

      Hope this helps.

      1. I am new to Azure and have couple of queries hoping to get answers for. By the way this is a great read to understand the basic concpets.
        (1) If a resource (Ex: VM and its data) has to be moved to another region, would moving the VM to resource group of another region suffice? I guess this shouldn’t work or not the right option.

        (2) back up the VM, delete the original VM, and recreate the VM in a different region. -> Should work however, guess it’s a time consuming process.

        Appreciate if you could answer this.

      2. Hi Pavan.

        1) Unfortunately moving VMs between Regions isn’t achievable by moving between Resource Groups. You can move between Resource Groups for logical grouping purposes but it will not actually move the underlying resource (in this case a VM).

        2) You can do this way, though Azure recently introduce cross-Region move support with Azure Site Recovery which is likely to be more straightforward to use.

        The definitive guide to moving VMs, which can be configured in a number of ways, is covered here: https://docs.microsoft.com/en-us/azure/site-recovery/azure-to-azure-move-overview

        Hope this helps!

    1. Thanks for the feedback Daniel, and yes, it does seem unclear why you’d consider Availability Zones (AZs) over Regions. Clearly a part of having AZs is to provide a clearly mapping to competitor constructs, but at their core Availability Zones simply provide a different way of creating solutions that are resilient to failures (or updates) to the underlying cloud hosting infrastructure. The best visualisation of the value of AZs is on the Azure Resiliency site in a PDF infographic. Hope this helps!

  3. Excellent!!!

    Thanks very much! for the detailed explanation. Your article helped me to understand Azure AD, Tenant and Subscriptions “in detail”..apart from Azure Geo & Regions with Availability Zones, as well

    Thanks again

  4. This piece of writing not only is succinctly written, but also helps make sense of terms that are not found explained so well elsewhere.

    Thank you very much Simon for this excellent write-up!!!

  5. Thanks Simon for clarifying the concept of moving VM’s between regions. Really appreciate your inputs and comments.

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