A parent gets charged when they pick up open spots but does not get charged for requesting standby spots. 

In the case where parent creates a transaction where they book a spot on Monday (because one is available) and create a standby request for Tuesday (since there is no spot available), they would be required to immediately pay for the Monday spot but not pay for Tuesday spot. However, if a spot opens on Tuesday and is fulfilled by this child, then they would automatically be charged at this time for the Tuesday spot. 

Parents should be aware of this as this is shown to them on the screen when they are booking spots.