Discount code not working Shopify: find why

The owner tests with a cart they already know: one item, their own address, a code they created that morning. A shopper builds a different cart. A code limited to one collection works on a shirt from that collection and does nothing for a mug the shopper adds beside it. A minimum subtotal fails on a cart that is just under it. A limit of one use per customer passes for the owner, who has never used the code, and fails for a shopper who already has.

• Open the discount's settings and read the minimum, the products or collections, the customer group and the use limits.
• Add or remove one item at a time in a failing cart until the code starts to apply, then note which item changed it.
• Check the start and end dates against today's date, and check the combination setting for other discounts.
• Retype the code by hand. A space copied from an email or a link can make a valid code fail.

A discount code is refused when the cart breaks a rule set on the discount itself. The usual rules are a minimum subtotal, a minimum quantity, a limit to certain products or collections, a start date that has not arrived or an end date that has passed, a cap on total uses or uses per customer, and a combination setting that blocks it when another discount is already in the cart. A typo is possible, but a code typed correctly that still fails usually fails on one of these rules.

Customer eligibility is the rule owners forget. A discount can be limited to certain customers or a customer group, so a guest who has not signed in may not qualify while an account you have tested with does. Check that setting before you assume the code is broken. A code that works for you and fails for a stranger often sits there.

Work in a private window, from the same link a shopper would use. Start with a cart that fails, remove one item and apply the code again. Then put that item back, remove a different one, and apply again. The step where the total begins to change points at the rule. A total that moves only when the scarf is in the cart means the code is limited to scarves. A total that will not move below one subtotal means a minimum. A code that works in a cart in the morning and fails in the same cart in the afternoon points at a use cap that was reached in between.

Write down each cart and what the total did, then open the discount and confirm the rule by name. If the settings match what the shopper was told, the fault is in the email, the landing page or the wording beside the code field, and the admin is correct. Owners often skip this step and edit the discount, which changes the rule for every shopper at once and hides the cause.

Give the visitor a cart a shopper would really build, such as a scarf and a candle, along with the task. The visitor adds the items, opens checkout, enters the code and reads the order summary. The report gives the step where the discount line stopped moving, with a screenshot of the summary and any message under the code field. Run a second visitor with a cart that should qualify, and the two reports show which item or minimum the code rejected.

The run stops at the payment step. It does not pay with a real card, and it cannot read your discount settings or your customer groups. For a code limited to a customer group, give the visitor a test account in that group on a paid run. A bot check can stop a visitor too, and the report marks that visitor as blocked by the site.

Checkout flow testing

Every new campaign adds rules: a higher minimum, a new collection, or a code reused in an email after it has hit its use cap. Rerun the same two carts after each change to see which one now fails. Run them on a preview address before the store goes live, so a shopper never meets the refusal first.