On Shopify, stacking multiple discounts together is not possible. This means that if you have a 15% discount, you can’t take advantage of the free shipping coupon on the same order.
This policy affects automatic discounts as well. So, say a product gets an automatic discount of 20%. Shoppers can’t manually add a discount code such as a free shipping code when checking out. Shopify would override the manual discount and let the automatic discount go through.
Gift cards are also considered a discount and cannot be used together with discount codes. So if you are eligible for a gift card of $50, you can’t also use a free shipping discount or another discount that marks off a percentage of the price.
Also, multiple discount codes aren’t allowed on Shopify. This restriction makes discount stacking difficult. But all hope is not lost. PickyStory has a solution that allows you to stack PickyStory discount codes with a manual code entered by your customers!