By the Integrated Business Systems engineering team · Last updated 27 October 2026
When a US company opens offices in Europe, one of the first questions is where its Microsoft 365 data lives. This guide explains how data location works and the options available.
A Microsoft 365 tenant's core data location is set when the tenant is created, based on the country chosen at sign-up. A US company's tenant normally stores its data in the US, including the mailboxes and files of European staff, unless additional options are used. You can check your tenant's data location in the Microsoft 365 admin center under Settings › Org settings › Organization profile › Data location.
For tenants located in the EU, Microsoft has committed to store and process customer data within the EU Data Boundary for its core cloud services. It applies to EU-based tenants, not to a US tenant that happens to have European users.
| Option | What it does | When it fits |
|---|---|---|
| Single US tenant | All data stored in the US location | Simplest; acceptable for many companies with appropriate transfer safeguards |
| Multi-Geo | Lets one tenant store specific users' mailboxes and OneDrive data in other regions, such as the EU | Larger organisations that want European users' data stored in Europe within one tenant |
| Separate EU tenant | A second tenant created with an EU location | Only when legal, regulatory or customer requirements demand separation; adds management overhead |
Multi-Geo and Advanced Data Residency are paid add-ons with eligibility requirements; check current licensing with Microsoft or your licensing partner.
Where data is stored matters less than who can access it and how. Strong identity controls (MFA, conditional access, least privilege), logging and encryption, plus a valid transfer mechanism for any access from outside the EU, are what auditors and customers usually ask about.
For most clients we keep one tenant, apply the same security policies to every office, and document data location and access so you can answer customer and auditor questions. Where Multi-Geo or a separate tenant is genuinely needed, we plan it as a project.
It applies to tenants located in the EU. A US-located tenant doesn't move to it automatically.
A tenant's core location generally can't simply be changed. Multi-Geo or a new tenant are the usual routes; plan either as a migration project.
It can be, with appropriate safeguards such as a valid transfer mechanism. See our GDPR guide and confirm with your advisers.
We run IT for the London offices of US and international companies: helpdesk, Microsoft 365 security, office networks and backups, under the same SLA as your other offices. Monitoring never switches off, and a vetted London field partner takes care of anything physical.
Many US companies run their European operations from Dublin. We run IT for those offices: helpdesk, Microsoft 365 security, networks and backups, under the same SLA as your US sites. We watch your systems day and night and send a vetted Dublin engineer when something needs a physical fix.
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