How to Set Up Microsoft Teams with Security Best Practices: 4 Essential Steps to Securing Your Business Communications

Microsoft Teams is now central to how modern businesses communicate, collaborate, and share information. But with that convenience comes risk. Teams is a core channel where financial data, internal documentation, and client conversations take place — and without the right security settings, it can be a soft target for cybercriminals.

Microsoft offers a strong set of built-in security tools, but many of them are not enabled by default. That means your organisation might be unknowingly exposing sensitive data or allowing unapproved access.

Here are four essential security practices with instructions from Microsoft that any business can implement quickly, without needing advanced IT skills or expensive tools.

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1. Multi-Factor Authentication (MFA): Your First Line of Defence

Passwords are no longer enough to keep your accounts secure. MFA dramatically strengthens your defences by requiring a second verification step, such as a code from a mobile app, before access is granted.

To enable Microsoft’s default MFA settings:

1. Sign in to the Microsoft Entra admin center as a Security Administrator.
2. Browse to Identity > Overview > Properties.
3. Select Manage security defaults.
4. Set Security defaults to Enabled.
5. Select Save.

MFA should be applied to all users, especially those with administrative or financial access.

Learn More about how to setup MFA by following Microsoft's Guide on Setting Up MFA for Microsoft 365.

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2. Guest Access: Control Who Has Access to What

Guest access is useful when working with external partners or contractors, but it must be managed carefully. Unrestricted guest permissions can allow access to internal conversations, files, or shared drives long after a project ends.

To configure this properly, follow Microsoft’s recommended steps:

1. Sign in to the Microsoft Teams admin center.
2. Select Users > Guest access.
3. Set Guest access to On only if needed.
4. Under Calling, Meeting, and Messaging, select On or Off depending on what features guests should be able to use.

It’s essential to regularly audit guest users and remove any who no longer require access. This helps ensure that only current, relevant collaborators remain active.

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Explore in depth the process of setting up guest access for documents from Microsoft.

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3. External Collaboration: Manage Who Can Share and Work with Your Team

When collaborating through Teams, users often share documents via SharePoint or OneDrive. If external sharing settings aren’t properly managed, unauthorised guests could gain access, even unintentionally.

Microsoft recommends configuring external collaboration settings using Entra ID (formerly Azure AD):

1. Sign in to Microsoft Entra External ID.
2. Expand External identities in the left navigation pane.
3. Select External collaboration settings.
4. Ensure one of the following is selected:
   • Member users and users assigned to specific admin roles can invite guest users
   • Anyone in the organisation can invite guests (only if strictly required)
5. Select Save after making changes.

Also review the Collaboration restrictions section to ensure you’re not unintentionally allowing access from blocked or unknown domains. This ensures external users can collaborate only when invited by authorised staff and with appropriate access limits in place.

Follow Microsoft’s Guest Collaboration Guide and Video To Learn More About Setting This Up.

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4. Admin Role Review: Avoid Over-Privileged Access

Granting admin access too broadly can lead to serious risk if one of those accounts is compromised. Every admin role gives elevated privileges that could allow changes across the entire Microsoft environment.

To review admin access:

1. While signed into Microsoft 365, open the app launcher and select Admin.
2. Go to the Microsoft 365 admin center.
3. Navigate to Users > Active users.
4. Select any user and view their assigned roles. Remove admin privileges that are no longer needed.

Learn More About Admin Roles & Access in Microsoft.

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Only trusted personnel should hold administrator roles, and those accounts must always use MFA. There are the recommendations for user settings from Microsoft:

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Why Secure Teams Settings Matter

Microsoft Teams is part of the broader Microsoft 365 ecosystem, which offers strong, enterprise-grade security features across its services. However, many of those protections are only effective when properly configured. Out of the box, Teams is built to be flexible and collaborative, which is great for productivity, but it can also introduce risks if access, sharing, and user roles aren't carefully managed.

The reality is, most security incidents in Microsoft 365 environments don’t stem from technical failure, they result from misconfigurations, overly permissive access, or users sharing content without understanding the exposure. Even well-meaning staff can accidentally invite guests, share files externally, or overlook suspicious account activity if safeguards aren’t in place.

By enabling foundational security settings like MFA, access restrictions, and external collaboration policies, businesses can significantly reduce their risk surface without disrupting how people work. These controls don’t slow things down, they make Teams a safer, more controlled environment for your staff, clients, and data.
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Need Help Securing Microsoft Teams?

At Superior IT, we help Australian businesses configure Microsoft Teams the right way — from access control and file sharing to advanced monitoring and compliance with the Cyber Security Act 2024.

Our Microsoft 365 security services are designed to simplify collaboration without compromising your data.

Call Us To Get Started: 1300 93 77 49

Email: info@superiorit.com.au

Microsoft Teams Security Solutions: superiorit.com.au/services/microsoft-teams