I apologize if this has already been addressed - I did a search but didn't find any "fix."

I have to charge sales tax on goods and shipping. I understand how ZC calculates tax: (goods * tax_rate) + (shipping * tax_rate) = Total_Sales_Tax.

This posed a slight problem when I filed my taxes to the state. The state only has one field for gross sales, so that includes goods and shipping. This results in slight rounding problems (slight for now since my sales volume is low).

Example:
Goods value: $31.00
Shipping: $4.50
ZC tax: $2.39

Gross sales I report to the state: $35.50
Tax (6.75%): 2.39625 rounded to $2.40.

So the difference of a penny or 2 added up to about 20c total.

Is there a code change to calculate tax based on goods value and shipping combined instead of calculating them separately then adding?

TIA!