It is possible to over book the Club by making manual bookings in school, when you are booking in the club members please make sure there is space before confirming the booking.
We are currently aware of an anomaly when two bookings are processed at identical times. This may occasionally overbook the club, for example sibling bookings.
Whilst we work to rectify this, we recommend adjusting the limited places or restrict the time they can book up to so this gives the school time to check if there are any over bookings. Both of these can be amended via the Club Settings menu.
Another option would be to ask the parents to checkout/pay after they have booked the sessions for one sibling, and go back in and book and pay for the second sibling which would prevent any over booking.