If your event is more than 30 days away, $100 is charged when you book. It reserves the date and counts toward your total.
The rest is charged automatically to the same card 30 days before your event. If that day is more than a week away we email you first with the amount and the date, so it is never a surprise. (Book just over 30 days out and the two land close together — your event page always shows what is owed and when.)
Booking closer than 30 days out? Then the full price is charged when you book, and there is nothing left to pay later.
If the card is declined we email you a link to pay it and try once more two days later. The $100 is not refundable, so if a balance goes unpaid until 23 days before the event, the booking is cancelled and the $100 is kept.