Microsoft 365 has transformed the way we work. It provides secure access from virtually any device, supports hybrid working and makes collaboration easy. Teams can share, edit and communicate without being tied to an office. But this flexibility brings more risk: cyber threats and unauthorised access are amplified when work happens everywhere.
Convenience comes at a cost
The same freedom that lets teams collaborate from anywhere also opens doors for attackers. A single compromised account can lead to data breaches, ransomware and reputational damage.
How do we balance accessibility with security?
The solution: Conditional Access
Many tools can protect your accounts and data, but one of the most important things any business can do is set up solid Conditional Access policies. Conditional Access lets organisations enforce granular policies that adapt to user context, location, device and risk level, without sacrificing productivity. Think of it as a security gate that only opens under the right conditions.
Conditional Access is included by default in many Microsoft 365 licences, which you may already be paying for.
Best practices for Conditional Access
Location-based restrictions
Limit access to trusted IP ranges, such as office networks or UK-based addresses. This reduces exposure to foreign attacks and suspicious logins. Even if a user gives their credentials to a phishing site, this one policy should give you enough time to reset the user’s credentials before any data is compromised.
Require MFA for every user
MFA is non-negotiable. Prefer modern methods like FIDO2 security keys or the Microsoft Authenticator app over SMS, which is vulnerable to SIM swapping. Paired with location-based restrictions, this gives your users a much stronger security posture.
Block legacy authentication
Disable older protocols that bypass MFA, such as POP and IMAP.
Monitor and adjust
Conditional Access is not set-and-forget. Review sign-in logs regularly and adapt policies as threats evolve.
Cyber threats are not slowing down, and neither should your business. Microsoft 365 gives you great flexibility, but that flexibility needs guardrails. Conditional Access is more than a feature, it is a strategy. By enforcing location-based restrictions, requiring MFA for every user and blocking legacy authentication, you create a security posture that keeps productivity high and risk low.
Start today: review your policies, tighten your controls, and make sure only the right people have the right access, every time.
Odyssey’s team has extensive experience managing not just Conditional Access, but your entire network security posture. For more information, call us on 01642 661888.