As a Project Admin, you are able to reserve a credit to a group for exclusive use by that group only. This is useful for when you want to pre-purchase credits in advance and allow your Group Coordinators the flexibility to activate/schedule them on a Flexbox when it suits their needs.
To do this, navigate to the master credits page where you can list all credits within your project. From here you can use the Group dropdown to assign an inactive (unused) credit to a Group.
Note: the dropdown will only appear for unused credits, since credits that have already been activated have their group fixed to the group of the Flexbox.
Once you have done this, the credit will be available for your Project Admins or Group Coordinators to activate from within that Group.