Add a coupon field in the truck or naturally display a “Have a markdown code?” link under the checkout button. Work with Shopify discounts. Savings before checkout: Clients can apply limits before they check out. Impending reserve funds in the truck. Discounts stacked in one code: Carter’s Smart Deals allow you to stack limits inside one code (markdown % + free shipping, layered limits, % rebate up to $X, etc.).