Microsoft 365 Copilot or your own AI environment?
Short answer
Microsoft 365 Copilot is strong when your work already lives in Microsoft 365: it uses your mail, documents and Teams chats and runs inside the Microsoft cloud. Your own AI environment is stronger when data must not leave your organisation, or when you do not want to depend on one US vendor. In 2025 Microsoft stated under oath that it cannot guarantee European data is never handed to US authorities.
What Microsoft 365 Copilot does well
Copilot sits in the programs staff already use all day: Outlook, Word, Excel, Teams. It can summarise a meeting, draft an email from a thread, or search documents the user already has access to. For organisations that run entirely on Microsoft 365, that is a big advantage: no new environment, no extra login.
Microsoft processes Copilot data within its own cloud, with the EU Data Boundary for European customers, and does not use customer data to train the foundation models. That is a fundamentally different level from a personal account with a free chatbot.
What to watch out for
Access rights become visible. Copilot finds everything a user has access to. Overly broad rights on SharePoint and Teams, unnoticed for years, suddenly become searchable. A clean-up of permissions often comes before a responsible roll-out.
Not all privacy risks are gone. In December 2024 the Dutch education and research cooperative SURF and the Dutch government’s strategic vendor management (SLM Rijk) published a DPIA on Microsoft 365 Copilot with four high risks. After improvements by Microsoft, two remained in September 2025, rated medium (orange): inaccurate personal data in answers, and the retention period of diagnostic data about use. SURF advises institutions to use Copilot cautiously and weigh it per use case.
The CLOUD Act. Microsoft is a US company and subject to the US CLOUD Act, which allows US authorities to demand data that a US provider controls, even when it is stored in Europe. In June 2025 the legal director of Microsoft France stated under oath before the French Senate that he could not guarantee that French citizens’ data would never be handed to US authorities without the French authorities’ consent. Microsoft added that this had not happened in practice.
Copilot and your own AI environment side by side
| Microsoft 365 Copilot | Own AI environment (private AI) | |
|---|---|---|
| Where does the model run? | In the Microsoft cloud | On a node of your own in your server room, or dedicated in a European datacentre |
| Who processes the content? | Microsoft, as processor | Only your organisation |
| Jurisdiction | US vendor, subject to the CLOUD Act | Your own organisation |
| Models | Chosen by Microsoft | Open-weight models you choose (Llama, Mistral, Qwen) |
| Integration with Microsoft 365 | Deep, directly in Outlook, Word and Teams | Through connectors and automations |
| Logging and insight | Through Microsoft Purview, within the platform’s possibilities | Full audit trail under your own control, with export to your SIEM |
| Cost model | Licence per user per month | Own hardware and operations; more expensive, but not per user |
When do you choose which?
Copilot fits when your work mostly happens in Microsoft 365, your data is not especially sensitive, and you have already accepted dependence on Microsoft for mail and documents.
Your own AI environment fits when you work with data that must not leave your organisation: patient data (AI in healthcare), material under professional secrecy (AI for law firms), or data for which your supervisor sets outsourcing requirements (AI and DORA). And when you want to keep the choice of models and vendor with yourself.
It does not have to be either-or. Many organisations use Copilot for general office work, and their own environment for the processes with the most sensitive data. At werqly that environment runs on a node of your own, managed through werqly AI Control. Your IT department decides per role which model and which data are available.
Frequently asked questions
Questions on this topic
Is Microsoft 365 Copilot GDPR-compliant?
Copilot makes GDPR-compliant use possible, but not automatically. After improvements in 2025, SURF and SLM Rijk still saw two medium risks: inaccurate personal data in answers and the retention period of diagnostic data. Your own DPIA and cleaned-up access rights are advisable.
Can US authorities access our data in Microsoft 365?
Under the CLOUD Act, US authorities can require a US provider to hand over data it controls, even when stored in Europe. In 2025 Microsoft France stated under oath that it could not rule this out, adding that it had not happened in practice.
Can your own AI environment work with Microsoft 365?
Yes. Your own AI environment can work with mail, documents and Teams through connectors, and you can build automations that process documents from SharePoint. Processing by the model then happens on your own node.
Is your own AI environment more expensive than Copilot?
Usually, yes. You pay for your own hardware and operations instead of a licence per user. Organisations do not choose it to save money, but because data must not leave their environment and they do not want to depend on one vendor.
Sources
- SURF — Privacy risks Microsoft 365 Copilot remain orange despite improvements (2025)
- The Register — Microsoft admits it “cannot guarantee” data sovereignty (July 2025)
- U.S. Department of Justice — The CLOUD Act (resources)
- Microsoft — Data, privacy and security for Microsoft 365 Copilot
This article is general information, not legal advice. Rules and guidance change; check the sources listed or ask your lawyer or DPO if in doubt.