Multi-factor authentication (MFA) is the single highest-ROI security control available to any business. Microsoft's own data shows it blocks over 99.9% of automated account compromise attacks. And yet, most small businesses still don't use it consistently.
Why Passwords Alone Don't Work Anymore
Billions of username/password combinations from past breaches are available for purchase on the dark web for essentially nothing. Attackers run these combinations against Microsoft 365, Google Workspace, VPNs, and banking portals continuously and automatically.
If any of your employees have ever reused a password — and statistically, most have — their credentials are likely already in one of those datasets.
What MFA Actually Does
MFA requires a second proof of identity beyond a password — typically a code from an authenticator app, a push notification, or a hardware key. Even if an attacker has a valid username and password, they can't complete the login without that second factor.
It doesn't make accounts impossible to compromise, but it eliminates the vast majority of credential-based attacks that target businesses like yours.
Where to Start
If you're not doing anything yet, prioritize in this order:
- Email (Microsoft 365 / Google Workspace) — Email is the master key to everything else. Password resets, financial instructions, and sensitive communications all flow through email. This is your highest-priority MFA deployment.
- VPN and remote access — Any remote access path into your network is an attacker's preferred entry point.
- Financial and banking systems — Accounts Payable fraud and wire transfer fraud are common outcomes of email compromise.
- Cloud applications — CRM, HR systems, and any SaaS applications with business-critical data.
Authenticator Apps vs. SMS
SMS text codes are better than nothing but are vulnerable to SIM-swapping attacks. For business use, authenticator apps (Microsoft Authenticator, Google Authenticator, Duo) are significantly more secure and are free. For high-privilege accounts, hardware keys (YubiKey) provide the strongest protection available.
The Employee Friction Problem
The biggest objection to MFA is that employees find it inconvenient. This friction is real but manageable. Modern MFA implementations using Conditional Access can be configured to only prompt for the second factor when a login looks unusual — new device, new location, after-hours access. On a trusted device at the office, users may never see an MFA prompt.
The question isn't whether MFA is inconvenient. It's whether a business email compromise incident is more inconvenient.