Someone else booked it first, or the court was taken while they were paying. They need to pick another time. A booking that goes unpaid past the hold time is released for others.
How players reserve a court, and how court cancellations are refunded
Players reserve a court from the Reserve a court tab on your club page: they pick a day and an open time, choose the court and session length, and tap Reserve. A player who cancels before your free cancellation cutoff gets their money back, less the Service fee they paid at checkout. After the cutoff there is no refund.
The Reserve a court tab appears once your club accepts court reservations and has at least one court. If you turned on Members-only booking, players have to join your club first.
Reserve a court
On the club page, open Reserve a court.
Pick a day with the date arrows or the date picker. Only days inside your booking window can be booked.
Tap an open time on the schedule.
In Reserve a court, choose the Court (if more than one is free) and the Session length, and add any extras your club rents out.
Optionally add others under Playing with you (optional).
Tap Reserve for a free booking, or Reserve with the price for a paid one, and pay by card.
Before paying, the player sees the cancellation terms, including the time the booking stops being refundable. A paid court is held for the player while they pay (15 minutes by default). Their booking then appears under Your upcoming reservations.
Split the cost or use member perks
Split the cost evenly: once players are added to a paid booking, the booker can split it. They pay one share now. Each other player is billed their share on their club account, at their own membership's rate. This only works with members of your club.
If you turned on Pay only your share, the booker can also split by the number of players without adding names. They pay one share, and you collect the rest from the others.
Apply account credit uses the player's club credit.
Use my included court time uses court time that comes with their membership.
Cancel a reservation
Under Your upcoming reservations, tap Details on the booking.
Tap Cancel reservation.
Confirm with Yes, cancel it.
Players can't cancel a booking once it has started. They need to ask the club to cancel it.
How refunds work when a player cancels
There is one cutoff, set under Free cancellation in Booking rules (2 hours before by default). A membership tier can have its own cutoff. The cutoff shown when the player booked is the one that applies.
Before the cutoff: the player gets back what they paid, less the Service fee. If you turned off Players pay the card processing fee, there is no service fee, so they get a full refund.
After the cutoff: the booking is cancelled with no refund.
Nothing paid: the court is released and there is nothing to refund.
When your club cancels a booking, you choose where the money goes, and the player can get every cent back.
A player says the time they wanted is no longer available
A player can't book even though the court is open
Check their membership tier's limits (bookings per day, bookings per week, maximum booking length and maximum active bookings) and the club's Max active per member. A court set to staff only can't be booked online at all.