ashuwp

Ashuwp_Invitation_Code is a wordpress plugin, It helps adding invitation codes for your site. 
Worked at multiste, Compatibility with buddypress.
<h4>Plugin Page</h4>
<a href="http://www.ashuwp.com/package/ashuwp_invitation_code" rel="nofollow ugc">Plugin page</a> 
<a href="http://register.ashuwp.com/" rel="nofollow ugc">Demo</a>

Ashuwp invitaion code

Ashuwp_Invitation_Code is a wordpress plugin, It helps adding invitation codes for your site.

nimeshrmr

<a href="http://profileplugin.com/invitation-codes-addon/" rel="nofollow ugc">Invitation Codes for User Profiles Made Easy</a> is a free addon provided for limiting the registration only to invited users. Admin can enable/disable invitation code based registration anytime. Once enabled, users without valid invitation code can?t create a new registration.
Please note that this is an addon for <a href="https://goo.gl/Dtqxsx" rel="nofollow ugc">User Profiles Made Easy</a> plugin and you need at least UPME version 2.1.10 to use it.
<blockquote>
Main Features
<ul>
<li>Create and manage invitation codes and quota</li>
<li>Send invitations to emails from WordPress backend</li>
<li>Limit registration to invited users</li>
</ul>
</blockquote>

Invitation Codes for User Profiles Made Easy

Limit WordPress User Registration to Invited Users with User Profiles Made Easy.

Ashuwp invitaion code vs Invitation Codes for User Profiles Made Easy