← Back to Blog
Cybersecurity

Why MFA Is No Longer Optional for Microsoft 365

March 12, 2026 · By IT Works MSP · 6 min read
Cybersecurity and MFA for Microsoft 365

If your business is still relying on passwords alone to protect Microsoft 365 accounts, you are one compromised credential away from a serious breach. Microsoft has made it clear: multi-factor authentication is no longer optional, and businesses that haven't enabled it are running a risk they can no longer afford to ignore.

Here's what MFA actually does, why it matters more than most business owners realize, and how to roll it out without disrupting your team.

Why Passwords Alone Fail

The problem isn't that your employees are choosing bad passwords — it's that even strong passwords can be compromised in ways that have nothing to do with guessing. Credential attacks today typically fall into a few categories:

None of these attacks require technical sophistication. They're automated, cheap to run, and effective against organizations that haven't layered additional verification on top of the password.

By the numbers: Microsoft reports that MFA blocks over 99.9% of automated account compromise attacks. Accounts without MFA are more than 20 times more likely to be compromised than those with it enabled.

What MFA Actually Does

Multi-factor authentication works by requiring a second form of verification in addition to the password. Even if an attacker has your password, they can't complete the login without access to that second factor — typically your phone.

For Microsoft 365, the most common second factors are:

Microsoft Is Now Enforcing It

Starting in 2024, Microsoft began enforcing MFA for Microsoft 365 tenants and Azure portals as part of their Secure Future Initiative. Tenants that hadn't enabled it received notices and, in many cases, had MFA automatically enabled on their behalf with a grace period to configure it properly.

For businesses that run on Microsoft 365 — email, Teams, SharePoint, OneDrive — this means that MFA configuration is no longer something you can defer. It's infrastructure, the same way antivirus or backup is infrastructure.

The Impact on Your Team

The biggest objection we hear from business owners is that MFA will slow their team down. In practice, once employees have the Authenticator app set up, the additional friction is about three seconds per login. Most people find it becomes second nature within a week.

The bigger disruption comes from a poor rollout — users getting locked out, no clear instructions, IT scrambling to re-enroll people. That's entirely avoidable with a planned deployment.

A Simple Rollout Approach

  1. Enable MFA in your Microsoft 365 admin centre (or use Conditional Access policies if you're on a Business Premium or above plan).
  2. Send employees a short guide explaining what to expect and how to install the Authenticator app before the change goes live.
  3. Set an enforcement date and give people 1-2 weeks to self-enroll.
  4. Have IT available on the enforcement date for the handful of people who need help.

For organizations with 20 or more employees, a managed rollout handled by your IT provider typically takes half a day and results in near-zero disruption.

What About Admin Accounts?

If there's one account that absolutely cannot go without MFA, it's your Microsoft 365 global administrator account. Admin accounts have access to everything — email, files, user management, billing. A compromised admin account is a full organizational breach. We recommend that admin accounts use hardware keys or at minimum have MFA enforced through Conditional Access policies, separate from standard user accounts.

Quick check: Log into your Microsoft 365 admin centre and navigate to Users > Active users. Select any user and click "Manage multifactor authentication." If most users show "Disabled," you have work to do.

Beyond MFA: What Else Should You Have in Place

MFA is the most impactful single security control you can add to Microsoft 365, but it doesn't stand alone. A well-configured Microsoft 365 environment also includes:

If you're not sure where your Microsoft 365 environment stands, a security assessment can surface the gaps quickly. Most of our clients are surprised by what they find — not because their teams are negligent, but because Microsoft 365 ships with a lot of settings that aren't configured for security out of the box.

Not Sure if Your M365 Is Configured Correctly?

We review your Microsoft 365 security settings, MFA status, and access controls as part of a free IT assessment. No pitch, no pressure — just an honest look at where things stand.

Book Your Free Assessment