Secondary Providers can be assigned to old charts with past data or new charts without being charged by doing the following:
The Primary provider (the person who created the chart) should move the chart into the Inactive folder first.
Just check the chart you wish to move, and then click the "Move" button and choose move to "Inactive" Charts:
Then the Primary provider needs to assign the Secondary provider to the chart that in the Inactive folder.
Just click on the "Invite" button of the chart in your Inactive folder.
Type the email address of the Secondary provider in the "Secondary Providers" field.
Then click on the "Invite" button.
After this the Secondary provider will need to confirm the chart and it will automatically show in their Inactive folder.
In this way the Secondary provider will not be charged for this chart.
Providers are only charged when they have 2 or more charts in their Active folder.
Now, the Secondary provider will be able to see all the past information about the chart (classes, scores, trends and so on) by going into their Inactive folder.