Which rate is used when calculating sales tax?
The Sales Tax is calculated using the rate on the document (Sales Order, Sales Quote, Sales Invoice, Cash Sale). The rate is located on the last tab labeled "Taxes".
Ok, then why is there a rate on the Customer Card?
The rate on the Customer Card is the default sales tax rate for this customer. When creating a document for this customer, this is the rate that will display on the document. You can always change it.
Alright, how about the rate in the Settings? What the heck is that for?
When creating a new customer, this rate will be copied to the card by default so that you don't have to enter it. It can be changed on the customer card. If you don't like this behavior, leave the sales tax field in setting blank and no rate will be copied.
Is Sales Tax calculated using the rate at the Billing Address or Shipping Address?
Good question. It all depends on :
a) What you are shipping?
b) Where you are shipping it and
c) where you are billing it to?
Tax laws vary GREATLY by state and locality and the rates may be different between two addresses that sit across the street from each other in certain parts of the country. We HIGHLY recommend using our Sales Tax integration with Avalara for these complicated situations. You can find out more about this here. In short, you don't have to think about it. Save your order and the right sales tax will be put on it. Reporting and payment is included with the subscription and if they're wrong, they will pay the fine.