Error: Discount code isn’t valid for the items in your cart.
We've found 2 cases in which Shopify returns this error:
Case 1. The updated cart doesn't meet the threshold for a discount to be added.
Vitals calculate the discounts on the cart page when the checkout button is clicked, and the visitor is redirected to checkout. So, when a product is eligible for Volume Discount, a corresponding discount is added to the cart. The same applies to the Product Bundles app.
Every time you make changes to your cart page, if your cart is eligible for a new Product Bundle or Volume discount, we assign a new discount code at checkout.
However, if the cart isn't eligible for a discount anymore, we can't automatically delete the discount code that was already added. Shopify will detect that your cart's contents no longer match the rule for which the discount was created, so it will throw out an error to let you know that the discount code is no longer eligible.
Please check this screen recording to see how the error occurs:
Case 2. The visitor remains on the checkout page for more than 24 hours and proceeds to the next steps.
This scenario was extremely difficult to replicate. It would require the visitor to add eligible products to the cart, proceed to checkout, leave the page open for at least 24 hours, and then move forward with the purchase. This may occur because lots of discount codes are generated every day, and we delete them after they expire, 24 hours after being generated.
If instead, the visitor left the cart page open indefinitely, a new discount code would be generated when the checkout button is clicked and applied successfully to the checkout.