During Checkout, you can apply sales tax and discounts.
To apply sales tax, you’ll need to first set up one or more sales tax rates in QuickBooks Online. You’ll find this under the Sales Tax tab in QuickBooks Online. After you add a sales tax rate, return to Full Slate, refresh the sync under Setup > QuickBooks Sync, and you should see your sales tax rate next time you visit Checkout.
To apply a discount, select from ‘Discount percent’ and ‘Discount value’ and then enter your desired percentage or dollar value.
You can choose to apply the discount before or after sales tax by clicking the up-down-arrow icon on the left side of these fields.