Entering Customer Account Line Items 
Once you have entered the data for the document header, you can enter the line items for the customer account.
To enter each customer item you specify a posting key and account number and, if necessary, a special G/L indicator and a new company code on the screen prior to entering that item. On the next screen you enter all additional data for the line item.
For each item, you must enter:
Posting Key for the Customer Invoice Customer Account NumberEnter the following data if it is required:
Special G/L Indicators (Accounts Receivable) Output Tax in Customer Line Items Terms of Payment (Accounts Receivable) Terms of Payment for Holdback/Retainage (Accounts Receivable) Payment Control Data (Accounts Receivable) Dunning Data Allocations for Line Item Display (Accounts Receivable) Further Details for Customer Line Items