For an internal charge number to be generated for a reservation, the Create Internal Charge Number parameter must be set to On.

Reservations must be active (that is, the status must be Advanced Checked In or Checked In) to be located in the system when a third-party inquiry is made, or otherwise fit any Pre and Post Stay Charging rules. A room number does not need to be assigned for a reservation to be considered active.

If postings are made outside of the OPERA system, any third-party point of sale systems such as restaurants, gift shops, and theme parks must be integrated and configured to work with the OPERA system.