Gross margin is distiller revenue divided by net sales. Shipping collected and tax collected are paid by the customer. They are not distiller revenue and they are not subtracted from gross margin. Carrier cost is the pass-through offset to shipping collected.

Tie-out to Shopify: gross sales − discounts − returns = net sales; net sales + shipping + tax = total collected. Shipping and tax are collected from the customer. They are not distiller revenue. Shipping is after shipping discounts and shipping refunds.