Disclosed are methods, apparatus, systems, and computer-readable storage media for providing access to communities of users in an online social network. In some implementations, a server is configured to identify a user identity (ID), received from a computing device, as one of a plurality of first user identities (IDs) of first users belonging to a first community maintained on behalf of a first organization by a social networking system. The computing device can then be provided access to the first community. When a request to access a second community maintained on behalf of a second organization is received from the computing device, the user ID can be identified as one of a plurality of second user IDs of second users belonging to the second community. The computing device can then be provided access to the second community.