Techniques for invitations for establishing relationships are described. In at least some embodiments, an architecture is implemented which provides simple and integrated ways for establishing relationships between various entities. The architecture includes invitations that can be used to invite users to establish relationships with entities. A user that receives an invitation can interact with the invitation, such as to accept or decline an invitation to establish a relationship with an entity. If a user accepts an invitation, a relationship can be established between the user and an inviting entity. In at least some embodiments, the relationship can enable the user to perform various actions and/or access resources associated with the entity.