Microsoft Teams has become an integral part of everyday work for many companies. Chats, video conferences, meetings, contacts, tasks and appointments are all managed through a single interface. Particularly in hybrid working environments, Teams has therefore developed into a central tool for communication and collaboration.
There are good reasons for its widespread use: Teams is embedded in Microsoft 365, familiar to many users and easy to integrate into existing workflows. This offers companies a clear advantage. The platform simplifies coordination, shortens communication channels and brings together many of the functions employees need in their daily work.
However, this strength also presents a challenge: Teams is not only used for conversations and scheduling. Files are frequently shared, edited collaboratively and exchanged with internal or external parties. To many users, it appears as though these files are stored directly “in Teams”. In reality, other Microsoft services are involved in the background – particularly SharePoint and OneDrive.
This is practical for general collaboration in many cases. However, when sensitive files, confidential projects or external data exchange are involved, it is worth taking a closer look at the security of the services being used.
What is Microsoft Teams?
Microsoft Teams is a collaboration platform within Microsoft 365. It brings various Microsoft services together in a single interface and has therefore become the central starting point for day-to-day collaboration in many organizations. Instead of switching between numerous individual applications, employees can manage coordination, meetings, tasks and files in one place.
This consolidation is efficient. However, it can also result in requirements being mixed that should be considered separately. Communication and file storage are not the same – particularly when sensitive data is involved.
Teams is convenient – but how secure are the files stored through it?
From a user’s perspective, Microsoft Teams is convenient above all else. A team can be created quickly, a channel set up in just a few steps and a file shared within seconds. Colleagues can comment directly, work on documents together or involve external parties in discussions.
This is a major advantage for day-to-day collaboration. Teams reduces disruptions between different applications and creates an environment in which numerous work processes come together. For precisely this reason, it would be unrealistic to fundamentally question the use of Microsoft Teams in companies. The key question is therefore not: Should companies use Teams?
A better question is: Which data should actually be stored, shared and edited through Teams and the connected Microsoft 365 services?
When Teams becomes a file storage system
In practice, Teams is frequently used not only as a communication platform but also as a file storage system. Project documentation, presentations, quotations, contracts, meeting minutes, customer documents and internal coordination materials are shared directly in channels or chats.
This often happens naturally as part of the workflow. A file is attached to a chat, a document is uploaded to a channel or a folder is provided for a project team. For the people involved, this is simple and convenient.
This is generally less critical for information with a low protection requirement. However, the situation is different when sensitive documents are shared through Teams. These may include:
Contract documents
Personal data
Financial information
HR documents
Company information for external consultants
Confidential project documents
M&A or due diligence documents
Technical specifications or development data
In these cases, it is not enough for files simply to be shareable. What matters is where they are stored, who is given access, how permissions are managed and whether the exchange remains traceable.
SharePoint and OneDrive operate in the background
Many users perceive Teams as a central storage location. From a technical perspective, however, Teams primarily serves as the interface through which various Microsoft 365 services work together.
Files shared in Teams channels are generally stored via SharePoint online. Files shared in chats are connected to OneDrive. This distinction is barely visible to users in their daily work. For IT, data protection and compliance teams, however, it is highly relevant.
This results in different storage locations, permission models and responsibilities. A file may be stored in a team channel, shared through a private chat or made accessible through an external sharing link. As the number of teams, channels, chats and project groups grows, maintaining a clear overview becomes increasingly difficult.
Limited data sovereignty with SharePoint and OneDrive
Unclear storage locations and the general use of Microsoft-owned cloud storage services raise questions about data sovereignty. Microsoft 365 is a global cloud ecosystem operated by a US-based provider. In addition to general technical considerations, the legal framework governing data storage may therefore also be relevant to companies.
Under certain conditions, the CLOUD Act allows US authorities to request information from US-based providers – even when the data is stored outside the United States. For particularly sensitive information, this is another reason to carefully assess which data should be stored in Microsoft 365 and which would be better protected in a more controlled environment.
This is where the challenge begins: Teams feels like a single, central location. However, the underlying data storage structure is considerably more complex.
Why this matters for sensitive data
Basic storage and sharing functions are often not sufficient for sensitive files. Companies need to be able to determine where information is stored, who has access, who has made changes and how long external permissions remain active.
Typical questions include:
Who is permitted to access specific files?
Have external parties been invited?
Are existing sharing permissions still appropriate?
Have files also been shared through chats?
Are copies stored in personal OneDrive areas?
Who can download, edit or share documents?
How is project data deleted or archived once a project has been completed?
The more extensively Teams is used in daily work, the more frequently complex structures and scattered data repositories emerge. New teams are created, channels are added, files are shared, external parties are involved and completed projects are not always consistently cleaned up.
This does not mean that Teams is fundamentally unsuitable or insecure. It does mean, however, that sensitive data requires clear rules and deliberately selected storage locations.
This responsibility must not simply be shifted onto individual users. Companies need to establish secure processes and technical frameworks that make the correct handling of sensitive files as easy as possible – and ideally define it as the default. This is the principle behind “Security by Design”.
Communication and file storage should be considered separately
Microsoft Teams is highly suitable for communication, coordination and collaboration. Chats, video conferences, tasks, appointments and project communication can all be organized efficiently through the platform. However, the secure storage of sensitive files involves different requirements. These include access control, permission management, activity logs, secure external collaboration and clear data sovereignty.
It therefore makes sense to separate communication from file storage. Companies do not need to replace Microsoft Teams or require their employees to adopt new communication channels. Instead, they can focus on the area in which a particularly high level of protection is required: file storage and data exchange.
Not every file has the same protection requirements. Internal meeting minutes, a general project presentation and confidential contract documents each require different levels of security, access control and traceability.
Companies should clearly define:
Which data can be edited in Microsoft 365 without additional safeguards?
Which data requires additional control?
Which information should not be stored in SharePoint or OneDrive?
Which processes require a secure data room environment?
Making this distinction is an important step towards greater data security and data sovereignty – without giving up the advantages of Microsoft Teams.
A secure data room as an extension to Teams
A specialized data room solution addresses the areas in which Teams and conventional file storage systems reach their limits. It provides a protected environment for sensitive files, external collaboration and controlled data exchange.
A secure virtual data room helps companies provide confidential documents in a structured manner, manage access precisely and maintain traceable activity records.
This creates a clear division of responsibilities:
Microsoft Teams for chats, video conferences, tasks, appointments and coordination.
A secure data room for file storage, online editing, data exchange, business filesharing and access management.
For companies that already use Teams extensively, this combination improves the protection of sensitive files without unnecessarily changing established working practices.
Conclusion: Continue using Teams – while protecting sensitive data
Microsoft Teams is an important collaboration tool for many companies. The platform is familiar, efficient and firmly integrated into existing work processes. There is no need for this to change.
However, companies should take a closer look when sensitive files are shared and edited through Teams. SharePoint or OneDrive are often involved in the background. This is practical for many use cases. For particularly confidential data, however, a specialized data room solution is generally the better choice.
Companies therefore do not need to choose between Microsoft Teams and data security. The key is to deliberately separate communication from file storage:
Teams remains the familiar working environment. Sensitive files belong in a protected data room. This enables companies to combine convenience and productivity with effective data security.
Coming soon: netfiles for Microsoft Teams
To connect Microsoft Teams and secure data rooms even more effectively, netfiles is developing a new integration for Microsoft Teams.
With netfiles for Microsoft Teams, companies can continue using Microsoft Teams for communication, coordination and collaboration – while sensitive files are securely stored, managed and edited in netfiles Data Room.
The integration provides direct access to netfiles Data Room from within Microsoft Teams. Files are not stored in SharePoint or OneDrive but remain in the audited and ISO-certified netfiles data room.
This combines the familiar Teams interface with the security and control of netfiles Data Room.
Stay informed: Learn more about netfiles for Microsoft Teams