# 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. Cannot create or demote organization owners. * **Moderator**: Have the permissions of full members; additionally, many "Organization permissions" settings allow moderators to be given additional privileges or do so by default. * **Member**: Has access to all public streams. Member is the default role for most users. [Some organization settings](/help/restrict-permissions-of-new-members) allow an organization to restrict the permissions of **new members**; Members who do not have those restrictions are called **full members**. * **Guest**: Can only view or access streams they've been added to. Guest users interact with public streams as though they were private streams with shared history. Cannot create new streams or invite other users. * **Billing administrator**: The user who upgrades the organization to a paid plan is, in addition to their normal role, a billing administrator. Can manage billing in addition to the existing privileges. This allows someone from the billing department to manage billing without needing organization administrator permissions. 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). 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)