You will calculate the sale tax based strictly on a selling price and will list it in the invoice separately.
Your donation will not affect the calculation of the sales tax.
Please let me know if any clarification is needed.
I guess I am still confused- the selling price = 100$, so if I am understanding you correctly I would add 6.70$ to the bill for sales tax.
When I report my earnings to the state would I report 100$ or 80$, as 20$ has already gone to the charity?
that is correct - if the selling price = 100$ ans sales tax rate 6.7% - you would add 6.70$ to the bill for sales tax.
Your will report gross proceeds $100
than you will calculate your expenses and net profit.
Donation deductions are reported separately and would not affect the calculation of the business profit..