The users registered ( either admin or have the permission to accept the invite) within organization's in the GGC  account are the ones responsible for accepting an invite:

To accept the invite: 

1. Log into the portal via globalgrantcommunity.org or click on the link in the email sent to you                       

2. Click on ‘’invitations’’ on the left side menu options

3. click on ‘’accept’’ on the far-right hand side and confirm