Intro

Data within a Microsoft 365 tenant can be placed several places and for a customer it can be challenging to know where data is physically stored.

Whenever the abbreviation EUR is showed, for Microsoft 365 it spans across multiple datacenters:

• (vi) Vienna, Austria
• (he) Helsinki, Finland
• (db) Dublin, Ireland
• (am) Amsterdam, the Netherlands

Quick way to show data locations

Microsoft provides a simple way of getting this info.

1. Sign in to Microsoft 365 Admin Center (https://admin.microsoft.com/Adminportal )
2. Navigate to Settings, Org Settings, Organization Profile and then Data location

Here you can see that data for this tenant is stored within EU.

Microsoft Services data locations – Microsoft Learn

Other Microsoft 365 services can be found is this article from Microsoft:
Data Residency to other Microsoft 365 Services – Microsoft 365 Enterprise | Microsoft Learn 

Dig deeper

But what if you would like to know exactly there data is placed within paired regions? We know that EU datacenters span across multiple regions. West Europe and North Europe beeing the 2 largest datacenters, but more locations are used aswell.

Entra ID

Source: Customer data storage and processing for European customers in Microsoft Entra ID – Microsoft Entra | Microsoft Learn 

Service	Denmark
EID Directory Management	Ireland Netherlands
Access ReviewsTerms of Use	Ireland Netherlands
App Proxy	Ireland Netherlands
Authentication	Ireland Netherlands
Entra ID Domain Services	Ireland Netherlands
B2B	California Ireland Netherlands Texas Virginia
B2C	Ireland Netherlands
Connect Health	Ireland Netherlands
Groups Management	Ireland Netherlands
Identity Protection	Ireland Netherlands
MFA	Ireland Netherlands Virginia Washington Wyoming
Privileged Identity Management	Ireland Netherlands
Reporting (Activity Logs)	Ireland Netherlands
Self Service Password Reset	Ireland Netherlands

Source: Is Your Office 365 Data Secure? Here’s Where Microsoft Stores It 

Exchange Online

1. Open PowerShell
2. Connect to Exchange Online with command
   Connect-ExchangeOnline
3. Run following command to show locations of mailboxes
   get-mailbox | select-object servername
4. See the output of the command
   
5. Compare output with below information

• vi stands for Vienna, Austria
• he stands for Helsinki, Finland
• db stands for Dublin, Ireland
• am stands for Amsterdam, the Netherlands

6. In our example, you can see that mailboxes in the same tenant, are located across multiple datacenter locations.