# Join a Zulip organization By default, Zulip organizations require an invitation to join. Organization administrators can also allow anyone to join without an invitation, and/or restrict user email addresses to a company domain. See [manage who can join and invite](/help/manage-who-can-join-and-invite). ## See if you need an invitation to join 1. Go to the Zulip URL of the organization. 1. Click **Sign up** at the top of the screen. 1. If you see a sign up form, invitations are not required! Otherwise, the page will say that you need an invitation to join. ## See if you need an email from a specific domain 1. Go to the Zulip URL of the organization. 1. Click **Sign up** at the top of the screen. 1. Try to create an account with your desired email address. 1. If your email address is not from an allowed domain, you will get an error message to that effect. ## Accept an invitation Invitations to Zulip organizations come by email. Look for an email from Zulip. It may take a few minutes for the invitation email to reach your inbox. ## Tips * If you are joining multiple Zulip organizations, we recommend using the [Zulip Desktop app](../apps). The desktop app makes it easy to switch between different organizations. * If your company uses single sign-on (SSO) authentication for Zulip, these instructions may not apply. Try going to your company's Zulip URL to see if there are instructions there; otherwise contact your manager or IT department for company-specific instructions.