I am a sales agent and all of my invoices contain a sales commission componant at various % levels, depending on my agreement with the principle.
I can find no facility that allows me to automatically calculate this and as such, I am doing all the calculations in Excel and then transferring that into the INVOICE ITEMS field on the invoice and typing the result into the amount column.
QB SE UK will calculate mileage using the user input mileage rate. Why can't it do the same for commission? I would imagine that there are thousands of people whom work on a commission basis.