ClassroomParent treats a parent as part of the current school year when at least one of their students is in a classroom for that year. Parents whose students were only in your school in earlier years can still sign in and view those years, but they can't:
These parents can still pay what they already owe from before the year changed: costs for permission slips they completed, and store orders left pending cash or check payment. The dues Join Now button is hidden for them, and permission slips from past years no longer show up in their to-do list.
School admins are never restricted, even if they are also a parent whose students have left the school. If a parent tells you they can't use the store or pay dues but their student is enrolled this year, check that the student has been placed in a classroom for the current school year.