Microsoft 365 E3 contains the Office productivity suite plus core security capabilities. E3 can be topped up with security and compliance licensing add-ons to access some E5 tech without making the full jump to an E5 licence. Microsoft 365 E5 is the complete suite of productivity, advanced security, compliance, voice, and analytical capabilities.

Office 365 E3 licensing gives you access to productivity tools and secure storage, but E5 licensing does go a step further and provides access to additional features which your organisation might benefit from, particularly if security is a concern.