Turn On MFA for Your Whole Microsoft 365 Company

Most breaches start with one stolen password. This guide covers how to require multifactor authentication for your entire Microsoft 365 organization at once, with Security defaults or Conditional Access, and how to roll it out without catching your team off guard.

Why this is worth doing today

One stolen password shouldn’t be enough.

Passwords get stolen — Through phishing, reused passwords, or a data breach you never hear about.

MFA stops it anyway — Even with the password, a stranger still can’t get past the second step.

It’s often just off — Plenty of small businesses never turned it on for everyone.

Three ways to require it

Security defaults — Free, in every Microsoft 365 organization, the simplest place to start
Conditional Access — More control, needs a Microsoft Entra ID P1 or P2 license
Legacy per-user MFA — Available everywhere, but Microsoft doesn’t recommend it anymore

How to turn on MFA for your whole company, step by step

Start here

✓Security defaults: start here

Microsoft Entra admin center, Identity, Overview, Properties tab, Security defaults section.

WHAT TO DOTenants created after October 2019 often already have it on. Check first, don’t assume.

MFA for Microsoft 365 company: Security defaults: start here

What changes

→What your team will see

After signing in with their password, they’ll approve the sign-in from the Microsoft Authenticator app.

WHAT TO DOIt adds a few seconds. It doesn’t slow anyone down in any meaningful way.

What your team will see

Naples Computers

★Want us to roll it out for you?

We’ll turn it on the right way, with a heads-up to your team, so nobody gets locked out by surprise.

WHAT TO DOCall 239-513-1960, this is one of the fastest security wins there is.

Want us to roll it out for you?

Rolling it out smoothly

Give your team a heads-up first — A surprise security change generates a lot of confused calls
Have everyone install the Authenticator app — Before you flip the switch, not after
Revoke existing sign-in sessions — So everyone registers for MFA the next time they sign in

Recap: company-wide MFA

A stolen password shouldn’t be enough to get in
Security defaults is free, and the simplest place to start
Conditional Access gives more control, if you have the license
Give your team a heads-up, and have them install Authenticator first
Want it rolled out for you? Call Naples Computers

Printable quick guide

Turn on Company-Wide MFA Today (1-page quick guide PDF)

Frequently asked questions

What’s the easiest way to require MFA for my whole Microsoft 365 organization?

Security defaults, a free setting available in every Microsoft 365 organization through Microsoft Entra ID Free. Check or change it in the Microsoft Entra admin center: Identity, Overview, Properties tab, Security defaults section.

Is MFA already turned on for my company?

Possibly. Microsoft 365 tenants created after October 2019 have Security defaults turned on by default, but it’s worth checking rather than assuming, especially for an older tenant.

What’s the difference between Security defaults and Conditional Access?

Security defaults is a free, all-or-nothing setting available to every organization. Conditional Access, available with a Microsoft Entra ID P1 or P2 license, gives more granular control, such as requiring MFA only for risky sign-ins or exempting specific accounts.

How should I roll out company-wide MFA without catching my team off guard?

Give your team a heads-up before making the change, and have everyone install the Microsoft Authenticator app first. When you turn it on, revoke existing sign-in sessions so everyone registers for MFA the next time they sign in.

Before you turn on company-wide MFA, give your team a heads-up and have everyone install the Microsoft Authenticator app first. Then revoke existing sign-in sessions, so everyone registers for MFA the next time they sign in.