You specify the agreed down payments in the sales order. The down payment requests are deadlines for an item in a billing plan. It can only be used for order-related billing and not for delivery-related billing. You can control this in the billing rule:
For percentage milestone billing, the percentage share of the down payment is not included in the overall calculation of the individual milestone billing documents. The percentage specified for the down payment is always based on the total sum of the individual milestone billing documents.
As soon as you take away the billing block and save the sales order, a billing index is created for the individual dates.
An example is given for down payment processing for the documents in SD
and for postings in financial accounting. In order to keep things clear and simple, no country-specific VAT posting for down payments is contained in the example.
Down Payment Agreements in the Sales Order: