You define your split payment term in the Payment Terms window. You can enter due dates for each installment and specify discounts to assign to each line of your payment terms. You can also apply the tax and freight for the invoice to the first installment or prorate tax and freight over all of the installments.
Receivables lets you review invoice installments if the status of the invoice is Complete. You can review invoice installments in the Installments window.
Importing Invoices with Rules