Microsoft recently released something that we consider one of the major updates to Azure AD B2B management in years: “Cross-tenant access settings (preview)”. This brand-new feature is allowed to be consumed under the current MAU (monthly active users) licensing of Azure AD External Identities. You will need at least an Azure AD tenant that is linked to a subscription. An Azure AD Premium 1 or 2 license is required. The first 50.000 unique guest users are free each month.