Within the pitchup terms make clear a customer who fails to show or in some why causes an issue on the park is blacklisted from booking another holiday via Pitchup.
No shows are very annoying and as you keep the deposit the park really does loose out in this situations. Knowing they are blacklisted would be something
Robert Hicks commented
That would work
AdminPitchup.com (Admin, Pitchup.com) commented
How about a box in the portal where you can add email addresses from which you won't accept bookings?