# Roles and permissions There are several possible roles in a Zulip organization. * **Organization Owner**: Can manage users, public streams, organization settings, and billing. * **Organization Administrator**: Can manage users, public streams, and organization settings. Can upgrade the organization to a paid plan and become a billing admin. Cannot create or demote organization owners. * **Member**: Has access to all public streams. Can upgrade the organization to a paid plan and become a billing administrator. Member is the default role for most users. * **Billing Administrator**: Member or organization administrator who upgrades the organization to a paid plan becomes a billing administrator. Can manage billing in addition to the existing privileges. * **Guest**: Can only access streams they've been added to. Cannot create new streams or invite other users. For details of the access control model, see [Stream permissions](/help/stream-permissions). You can decide what role to invite a user as when you [send them an invitation](/help/invite-new-users#send-invitations). Organization owners can do anything an organization administrator can do. For brevity, we may sometimes refer to "organization administrators" being able to do something; unless stated explicitly, this means "organization owners and administrators" can do that thing. ## Billing and guests Guests are only available on Zulip on-premise and on paid plans for Zulip Cloud. There are two kinds of guest for billing purposes: * **Multi-stream guest**: Has been added to multiple streams. These guests are billed the same as regular members. * **Single-stream guest**: Has been added to only a single stream. If you have M paying users, you get 5M free single-stream guests. Similarly, if you have G single-stream guests, you'll get charged for G/5 users. Example: You have 8 members, 2 multi-stream guests, and 50 single-stream guests. You'll get charged for 10 users. Let's say you have 8 members, 2 multi-stream guests, and 51 single-stream guests. You'll get charged for 11 users. Single-stream guests are a new feature, and their permissions are likely to change over time. For example, single-stream guests can currently see the list of members in the organization, but we may remove that ability in the future. ## Related articles * [Stream permissions](/help/stream-permissions) * [Inviting new users](/help/invite-new-users)