What is Flex Routing within Microsoft 365 Copilot?

With the introduction of generative AI within Microsoft 365 Copilot, not only does the way you work change, but also how your data is processed. A term that is appearing increasingly often in this context is Flex Routing.

Although ecosystem Although this term is not always explicitly used in official documentation, it does describe an existing mechanism: AI requests are dynamically processed based on available capacity within Microsoft's global cloud network.

In practice, this means that a prompt you enter in Copilot is not necessarily processed in the same region where your data is stored. Microsoft makes a clear distinction here between storage (data at rest) and processing (data in processing), a nuance that is essential to properly understand this subject.

According to Microsoft Learn documentation on Azure OpenAI and Microsoft 365 services, processing can take place in multiple regions, depending on the load and availability of compute resources.

How does this work technically?

When you use Copilot — for example, in Word or Outlook — your prompt is forwarded to Microsoft's AI infrastructure, which runs largely on Azure OpenAI.

The request is processed there at a location where capacity is available at that moment. This can be within the same region, but also outside of it. For European tenants, this means that processing may take place outside the EU in some cases.

Microsoft indicates that this processing is temporary and that data is not permanently moved to another region. This aligns with how hyperscale cloud platforms function: workloads are distributed to optimize performance and availability.

Importantly, Microsoft does not position this behavior as an exception, but as an inherent part of cloud-based AI services.

Why does Microsoft use Flex Routing?

The main reason is scalability. Generative AI requires enormous computing power, and that capacity is not always evenly distributed across regions.

By using flexible routing, Microsoft can limit wait times and keep the user experience stable, even during peak load. Without this mechanism, you might experience delays or limited availability of Copilot functionality.

In addition, this approach makes it possible to deploy new AI capacity faster, regardless of where it is physically available. This is essential in a market where AI usage is growing rapidly.

What does this mean for privacy and GDPR?

Confusion often arises here. The suggestion that data is processed outside the EU quickly leads to the conclusion that this is contrary to the General Data Protection Regulation (GDPR), but that is not necessarily the case.

The GDPR does not prohibit international data transfers. What the law requires is that appropriate safeguards are in place when personal data leaves the EU. Microsoft indicates that this is managed through mechanisms such as Standard Contractual Clauses and the EU–US Data Privacy Framework.

This means that processing outside the EU may be legally permitted, provided these safeguards are correctly applied. At the same time, you as an organization remain responsible for compliance with the regulations.

For many organizations, the risk therefore lies not in the technology itself, but in assumptions. The idea that data “stays in the EU” is not always entirely tenable when it comes to processing in AI services.

Where are the key points of attention?

The most important point of attention is transparency. Although Microsoft indicates that data can be processed globally, it is not visible to you exactly where a specific prompt is processed. This makes it more difficult to achieve full control or auditability.

In addition, expectation management plays a role. In sectors such as finance, healthcare, or government, data sovereignty is often a strict requirement. In that context, the distinction between storage and processing can be relevant, even if international processing is legally permitted.

Compliance frameworks such as NIS2 and DORA also emphasize risk management and insight into data flows. Flex Routing makes this less predictable, which means you must explicitly include this in your documentation and risk assessments.

What does this mean from a licensing perspective?

Copilot is often approached as a functional extension within Microsoft 365, but in reality, with this license you also activate another method of data processing.

A Copilot license is therefore not only a right of use, but also an implicit choice regarding how Microsoft processes your data. This makes it important to look beyond just functionality and price.

In practice, it appears that this impact is not always fully taken into account in decision-making. That is precisely why it is essential that you understand what you are activating, not just what you are purchasing.

Practical advice for organizations

If you use or are considering Copilot, it is advisable to explicitly address this topic within your organization. Start by checking the relevant settings within your Microsoft 365 tenant and ensure you understand how the default configuration is set up.

In addition, it is advisable to review existing DPIAs and verify whether international data processing is correctly included therein. Coordination with legal and compliance teams is essential in this regard, especially if you operate in a regulated sector.

Finally, it helps to communicate clearly internally what Copilot does with data. Not to create unnecessary concerns, but to ensure that expectations and reality are aligned.

Ready to see how Snowflake works?

Flex Routing is not a hidden mechanism, but a logical consequence of how modern AI services function. It offers clear advantages in terms of performance and scalability, but also calls for a more realistic view of data residency.

For EU organizations, this is not a reason to avoid Copilot, but rather to make conscious choices and ask the right questions.

The core is simple: if you use AI, it is essential that you understand how that AI handles your data.