No, you can’t cancel a reservation. When a guest makes a booking, their reservation is confirmed immediately.
If a guest contacts you to cancel their booking, you can recommend they do this through their confirmation email or Booking.com profile. Guests can find this link on their confirmation.
For help on what to do when you have an overbooking, please contact the Customer Service Team.
If the guest didn't show up, mark the reservation as a No-show in the Reservations tab on the Extranet.
Invalid credit card:
For information on what to do when the guest has an invalid credit card, please contact the Customer Service Team.