So you found out you charged a customer tax but they were supposed to be Tax Exempt?
Here’s how to fix that.
Locate the invoice and open it.
Click the Return Button and return the items with the incorrect sales tax.
Re-sell the items with the updated tax information
You may need to update the sales tax by clicking the calculator on the positive quantity items to make sure they are not taxed.
Finally generate the invoice for the return items.
You can just hit finalize without hitting the pay option. Or refund the whole amount.
Next Generate invoice for the new total.
Then complete the invoice and pay any refund that may be due