On the evening of the 6th January 2020, a major update notification was sent out to businesses who are registered in the United Kingdom to inform them that the window for moving your core customer data to the UK data center geo is now open.
Where is my data at the moment?
If you aren't sure which geo your services are in at the moment, you can find out from your Office 365 Admin Center from the Organizational Profile. The org profile has now been tucked away slightly, at least it has in our tenancy, so to find it you will need to follow these steps:
Log in to your Office 365 Admin Center
On the let hand side, expand the settings menu (click on Show More if you don't see it)
Select Data location
On this screen you will then see where you content is stored, you may or may not be surprised where elements of your data is located when at rest. For UK customers, if you created your tenancy after the opening of the UK Data Centers (late 2017) then this probably isn't going to be an issue for you. However if you have a longer standing tenancy, then you may see that your data is stored within Europe.
Whilst the data stored within European Data Centers is still protected by EU Data Protection laws, GDPR etc, the fact that the data is not stored within the borders of the United Kingdom has often been a concern for customers.
Migrating to UK Data Centers
Whilst Microsoft endeavour to move services to native data centers over time, it is a long drawn out process which can take several years to complete.
Opting into the Migration
Every few years, the last being 2017, Microsoft will open a window whereby they will prioritise the migration of services and data from one geo to your local geo. This is very much an opt-in activity, and so if you don't then you will still be on the slow path of waiting for Microsoft to do it naturally over a number of years.
The window at the moment is to have your data to be migrated to the UK by 1st July 2022. Note that this is still a couple of years of effort for Microsoft to do this, and with best endeavors it may be complete before then, but aim for that date.
To opt in, you will still need to access your organisational profile within the Office 365 Admin Center, but this time rather than clicking on Data location, click on Data residency. This will display a check box indicating that you want to migrate by the above date.
Once you've submitted, you will be notified through the Message Center to say that it is completed. So now, it's a case of waiting for Microsoft.
If you want to learn more, you can visit the Microsoft page dedicated to this action: Moving core data to new Office 365 datacenter geos.