Hi Nguyen Hoang Yen
It is not very clear from your example and the exact business case. Is your requirement to combine Individual billing documents into a single collective invoice, then if so as suggested by Santosh Invoice list can be used. SAP sets a separate billing index for these Invoice List. You can also set special features for printing invoice lists, output determination and pricing.
Using the invoice list, you can group together several billing documents or several collective invoices at the end of a period specified in the customer master to form a new document. The invoice list is sent to and settled by a common payer.
Two types of invoice lists were created in the standard version:
LR for billing documents/debit memos
LG for credit memos
but if your requirement is to control how many billable line items should be eligible on a single billing document then this can be controlled via Billing Block functionality. Meaning if your single order has 10 billable line items and let's say you want to drop an invoice only for 5 line items then this can be done via billing block. please note that Std SAP uses the billing due date on the line items as the basis to create one collective billing document. SAP also offers a capability to combine multiple orders into single billing document based on Payer etc..
hope this helps.
regards,
Harsha
