Allow the ability to add expenses/overheads for a particular service/customer
For the purpose of calculating a more accurate revenue (or profit), please allow the ability to add expenses/overheads for a particular service or customer. For example, I could have various customers in multiple cities. I'd like to be able to add fuel costs as an expense so then when revenue/profit is calculated, I know how much I am getting. Also, a service could have its own expenses, for example renting an external product/service from a third-party vendor, or buying sundry items for that particular service.