Microsoft 365 MFA rollout checklist (small teams)

MFA is one of the highest-impact security changes you can ship quickly—but only if you roll it out predictably.

1) Inventory what will break

Before you flip switches:

• List shared mailboxes, service accounts, and legacy apps.
• Identify where users sign in (desktop Outlook, webmail, mobile, VPN, line-of-business apps).
• Confirm you have at least 2 global admins with strong authentication.

2) Choose the MFA method (don’t overcomplicate)

For most orgs:

• Prefer Authenticator app (number matching, biometric unlock).
• Keep SMS only as a temporary fallback.

3) Pilot first (5–10 users)

• Include someone from leadership + finance + an “average user”.
• Capture issues: mobile setup, old devices, third-party apps.

4) Communicate a clear cutover date

Share:

• What changes
• What users must do
• Where to get help

5) Enforce, then tighten

Start with “require MFA”, then improve:

• Conditional Access (location/device risk)
• Block legacy authentication
• Review sign-in logs weekly for 30 days

If you want help with a clean rollout (and documentation for audits), book a short call: /en/consultation