Bill Modify
In Bill Modify (27.3.2.2), you can modify the selection of invoices for any bill with the status Initial. You cannot modify bills that are already confirmed or closed. For bills with status Initial, you can modify three fields.
Bill Date
You can change the bill date. However, the date must be before the bill due date and it must be in the future.
Bill Due Date
You can change the bill due date but this field cannot contain an earlier date than the Bill Date field. If you do specify an earlier date or you specify a holiday or weekend, an error message is returned. If the billing schedule is set to update the invoice due date and you update the Bill Due Date field, the invoice due date is also changed. You can verify this change in Customer Invoice View.
Bill Collector
Use the lookup to assign a different bill collector to the bill. However, if a bill is assigned a collector, you cannot edit the bill to have no collector.
To remove an invoice from a bill, clear the Select field. To add an invoice to a bill, right-click and select Insert a new row. In the lookup, select the open invoice to add to the bill. The invoice must be for the same customer, currency, and entity. If the Update Invoice Due Date field is selected in Billing Schedule Create, the invoice is assigned the same due date as the other invoices on the bill.