انظري تعريف هذه الكلمة في سياقها:
Billing: total amount of business or investments (as of an advertising agency) within a given period.
https://www.merriam-webster.com/dictionary/billing

Billing: the total amount of the cost of goods or services billed to a customer, usually covering purchases made or services rendered within a specified period of time.
https://www.dictionary.com/browse/billing#:~:text=an act or ...