Registration Invite module provides admins an option to add new registrations through only invitations.

Installation

1. Registration Invite module depends on Invite module and User Referral module.
2. Copy the whole Registration Invite directory to your modules directory (e.g. DRUPAL_ROOT/sites/all/modules) and enable the Registration Invite module at [admin/modules].

Configuration

1. Visit user account settings page. [admin/config/people/accounts].
2. Under "Registration and cancellation > Who can register accounts?" section - select "New user registration by invitation only."
3. Under admin/structure/invite-types you can add invite type
4. Under /invite/add/ you can create new invites