What is MFA: Multi-Factor Authentication

Last updated: 2025-09-11

MFA stands for Multi-Factor Authentication. It’s a sign-in method that requires more than just a password (a single factor). With multi-factor authentication, two or more verification methods are combined. Two-factor authentication (2FA) is a common form of MFA.

What the “factors” mean (for verification)

  • Something you know — password, PIN, security question.
  • Something you have — mobile phone, authenticator app, hardware token, smart card.
  • Something you are — biometrics (fingerprint, face recognition, retina/iris scan).

Examples of multi‑factor authentication: 

  • Email sign‑in: enter your password (factor 1) and then a code from an authenticator app (e.g., Microsoft Authenticator, Google Authenticator) on your phone (factor 2).
  • Online banking: password + approve a push notification in a mobile banking app or enter a one-time code sent via SMS (text message).

In short

  • MFA = a little less convenient than passwords alone, but much more secure and less dependent on user discipline.
  • Improves protection against account takeover and identity theft.
  • Reduces the risk of successful attacks if passwords are phished or leaked.
  • Now standard in banking, cloud apps (Microsoft 365, Google Workspace), and business systems for small and mid-sized businesses (SMBs).