The Pro Rata feature is accessible in your activities configuration and can only be applied to session-based activities when there is a start and end date set up in the schedule.
To configure Pro Rata for an activity, go to Activities>Edit:
Click on New activity or select an existing activity.
In the Session section, check Enable purchasing this activity as a session and set the price for your activity.
Check Use this proportional deduction to enable Pro Rata.
Set an amount, select if this amount is entered in $ or %, then choose if it will be applied by day, week, month or class.
NOTE: This amount will be deducted depending on the passed occurrences. Ex: A session of 25 classes cost $200. If 10 classes have passed and you've set a pro rata of $10/class (10 x $10 = $100), clients will pay $100 ($200 - $100 = $100) for the 15 classes left.
Write down a minimum fee. Even when prorated, the activity's price will never go below this fee.
Check whether you allow discounts on the prorated activity.
When this option is activated, promotions tied to activity will apply until the cost reaches 0$. When this option is not activated, no promotion will apply as soon as the prorated cost start.