If your organization can only make one security improvement this year, make it this one.
Most account compromises don't happen because of a sophisticated attack — they happen because a password was reused, guessed, or exposed in an unrelated data breach. Multifactor authentication (MFA) closes that gap by requiring a second proof of identity, so a stolen password alone isn't enough to get in.
It's also one of the least disruptive security changes you can make. Most staff adjust within a day or two, and most modern collaboration platforms — including Microsoft 365 — support it natively at no additional cost.
If MFA isn't enabled across every account with access to email, financial systems, or client data, it belongs at the top of your list.