Charter, also called air taxi or ad-hoc flights require certification from the associated country's regulating body such as the FAA in the U.S. The regulations are differentiated from typical commercial/passenger service by offering a non-scheduled service. In the U.S. these flights are regulated under FAA Part 135. There are some cases where a charter operator can sell scheduled flights, but only in limited quantities.
After your initial enquiry you will be assigned a personal charter expert who will send you a selection of quotes for you to choose from. Each quote will have a clear breakdown of aircrafts and airports and reasons they have been selected for you. Should you wish to go ahead they will then book the aircraft and send you all the flight details including directions to the terminal and any other important information. They will be your first point of call for any further enquiries you may have up to the flight and, if possible, they will meet you at the terminal. From your initial quote you will be able to contact your account manager 24/7 (if on holiday you will be assigned another account manager to cover) so you can call from wherever, whenever you like.