1. Compare the milestone with periodic billing.
The concept of billing a customer on completion of a particular work milestone or activity is known as milestone billing. However, the concept of billing a customer on completion of a specified time period is known as periodic billing.
2. What happens if there is a negative posting in billing document?
Negative posting on the debit side reduces the credit side of an account. However, when a negative posting is made on the credit side, it reduces the debit side of an account.