===Custom Invoice Balance===
You can calculate an invoice balance only for certain upsell items or exclude upsell items from being added to the invoice balance. If you want to use this functionality you will need to add a status to the upsell item ( in SETTINGS->PROPERTIESBOOKING ENGINE->UPSELL ITEMS).
To set the status field of the invoice item include a pipe symbol | between the description text and the status text. For example Description of item | Status