As we move into 2026, Microsoft continues to evolve its powerful collaboration platform, Microsoft Teams. For businesses across Surrey and the South East, staying ahead of these changes is crucial for maintaining secure and efficient operations. One area seeing significant updates is how Teams handles external collaboration, and a recent notification, MC1183006, highlights important upcoming changes to the Teams admin centre.
Understanding Your External Collaboration Options in Teams
Microsoft 365 applications, especially Teams, have a history of rapid development. While the pace of change in the core Teams user interface might feel less frantic than it once did, the underlying administrative and configuration aspects are constantly being refined. This is a positive sign, indicating a commitment to improving functionality and security.
The latest development involves the introduction of three distinct modes for external collaboration settings within the Teams admin centre (TAC). This update, rolling out globally by the end of February 2026, aims to simplify how administrators manage who can collaborate with your organisation.
The Three Modes: Open, Controlled, and Custom
The new interface presents administrators with three primary modes for external collaboration:
- Open Mode: This mode, as the name suggests, is the most permissive. It allows for broad external collaboration, potentially including shared channels and guest access across various domains.
- Controlled Mode: This mode offers a more restricted approach. While still enabling external collaboration, it likely involves more defined parameters and approvals for who can connect.
- Custom Mode: This is the setting you’ll encounter if your organisation has previously made any specific adjustments to external collaboration policies. Essentially, it reflects your existing personalised configurations.
While “Open” and “Controlled” modes are predefined and intended to guide businesses, it’s unlikely many organisations will solely adopt these. Instead, they serve as excellent starting points or templates. The real power lies in understanding the granular settings within each mode, allowing you to tailor external collaboration precisely to your business needs.
The “So What?” for Your Surrey Business
Why is this important for businesses in Redhill, Reigate, and across Surrey? Secure and efficient external collaboration is no longer a ‘nice-to-have’; it’s a business imperative.
Enhancing Collaboration Security
One of the most significant benefits of these updates is enhanced security. In today’s connected world, it’s common to work with external partners, suppliers, and clients. However, without proper controls, this can open up vulnerabilities. The new modes in Teams allow for more deliberate management of these connections. For example, you can implement an “allow list” for specific external domains that your users are permitted to collaborate with. This drastically reduces the risk of unintentional exposure to untrusted entities.
Streamlining Guest Access
Managing guest access to your Teams channels and resources can be complex. The updated settings aim to simplify this process. Whether it’s providing temporary access to a contractor working on a specific project or enabling a long-term partnership, the new modes offer clearer pathways to grant and revoke access. This not only improves security but also boosts productivity by ensuring the right people have the right access at the right time.
Real-World Impact: A Scenario for a Marketing Agency
Imagine a growing marketing agency based in Surrey that frequently collaborates with freelance designers, videographers, and other specialist agencies for client projects. Previously, managing who could join their Teams channels and access project files was a manual and sometimes confusing process. They might have relied on broad guest access settings, which, while convenient, also carried inherent risks.
With the new external collaboration modes in Teams, this agency can now adopt a more strategic approach. They can select a “Controlled” mode as a baseline and then customise it further. They can create an explicit allow list for all approved external collaborators, ensuring that only trusted individuals from pre-vetted domains can join their projects. They can also set specific permissions for guest users, limiting their access to only the channels and files relevant to their contracted work. This not only strengthens their security posture but also provides peace of mind, knowing that sensitive client information remains protected while still facilitating essential external teamwork.
Beyond Teams: Understanding Wider Microsoft 365 Controls
It’s important to remember that while the Teams admin centre manages Teams-specific collaboration, some policies affecting external collaboration exist beyond TAC. For instance, Entra B2B Collaboration policies impact all Microsoft 365 applications. These broader controls, such as blocking guest invitations from specific domains, are managed through Entra ID (formerly Azure Active Directory).
This highlights a key point: managing Microsoft 365 effectively often requires looking beyond individual applications. Understanding how different services interact is vital for comprehensive IT management. As Rob Trueman, our IT Director here at Byte By Byte, often stresses, a holistic approach is essential for robust IT solutions.
Simplifying Tenant Management
Microsoft 365, and Teams in particular, offer a vast array of policies and settings. For administrators, this can sometimes feel overwhelming, especially for those new to the platform. The introduction of these simplified modes for external collaboration is a welcome step towards making tenant management more accessible. While administrators won’t be interacting with these settings daily, having them organised and presented in a clearer way is a significant improvement. It reduces the potential for misconfigurations and makes it easier to maintain a secure and efficient environment, especially for busy small to medium-sized businesses across the South East.
How Byte By Byte Can Help
Navigating these evolving Microsoft 365 settings can be time-consuming and complex. At Byte By Byte, your local Surrey IT partner, we understand the challenges businesses like yours face. Our team of certified experts has deep knowledge of Microsoft 365, including Teams, Exchange Online, SharePoint, and more. We can help you:
- Analyse your current external collaboration needs: We’ll work with you to understand who you collaborate with and what level of access is appropriate.
- Configure Teams external collaboration settings: We’ll ensure your settings are optimised for security and efficiency, utilising the new modes to your advantage.
- Implement broader Microsoft 365 security best practices: We look at your entire environment to ensure a cohesive security strategy.
- Keep your IT infrastructure up-to-date: We monitor Microsoft’s updates and proactively advise on how they impact your business.
Let us take the complexity out of your IT management so you can focus on running your business.