Troubleshoot bundles and discounts
Fix Combine product sets and bundles: discounts not applied, a set that cannot be added to the cart, sold out products and discount codes.
Applies to: Combine 4.2.0 and later. Added in: Combine 1.0.0. Last checked: 2026-10-13 against Combine 4.2.0.
Use this page when a Products set or a Products bundle section does not behave as expected. The sections only add products (and, with a discount code, the code) to the cart. Shopify decides whether a discount applies, so most fixes are in Shopify admin → Discounts.
The setup itself is on Discounts and bundles. What the sections cannot do is listed in Limits to know.
Why is the discount not applied to my set or bundle?
Because the cart does not meet the rule of the Shopify discount. Check these in order:
- The discount is active: its status is Active and today is within its active dates.
- Applies to matches the section: the same products as the set, or the bundle's collection (or the same products when the bundle uses Select products).
- Minimum quantity of items equals the number of products in the set, or the bundle's Minimum items required to get a discount.
- The method matches Discount type: an automatic discount for Automatic discount, a code discount for Discount code.
- Another discount in the cart does not block it. Shopify's combination settings decide which discounts can apply together.
The texts of the section ("Save $30 when buying 3 items") are only text. Changing them does not change the discount.
Why can customers not add the set to the cart?
Because a product of the set has no available variant chosen. The set button reads "Choose products first" until every product has an available variant selected, then "Add all to cart".
Unavailable variants are hidden, so a product that is sold out in every variant can never be chosen. Restock the product, or replace it in the set's Select products.
Why is the "Add to cart" button of the bundle greyed out?
Because the bundle panel still has an empty slot. The panel has as many slots as Minimum items required to get a discount, and the bundle can be added only when every slot holds a product. Customers fill the slots with Add to bundle on the product cards.
Why can customers not add more products to the bundle?
Because the panel is full, or the product is already in it.
- When every slot is full and Allow unlimited items is off, the rest of the grid is greyed out. Turn on Allow unlimited items to let customers add more.
- When Allow each product to be added only once to the bundle is on (the default), a product is greyed out once it is in the bundle. Turn it off to allow the same product in several slots.
Why does the discount code not show in the cart?
Because Discount type is still Automatic discount, the Discount code field is empty, or Shopify rejected the code. Check these in order:
- In the section, Discount type is Discount code and Discount code holds the code.
- The code is spelled exactly as in Shopify admin → Discounts.
- The code is active, not used up, and the cart meets its conditions (products and minimum quantity).
A code that Shopify rejects does not stop the purchase: the products stay in the cart without the saving. The theme then writes a warning in the browser console ("Discount … was not applied"), which helps when you test. Codes that were already in the cart stay applied.
Why does the discount also apply when customers buy the products separately?
Because Shopify does not know about the set or the bundle. An automatic discount applies to every cart that meets its rule, whether the products came from the set, the bundle or the product pages. To limit the saving to customers who use the section, use Discount type → Discount code with a code that is not published anywhere else.
Why is a fixed amount taken off every product of the bundle?
Because the Shopify discount applies the fixed amount to each eligible item. In the discount, select the option to apply the discount once per order. A percentage discount does not have this problem.
Why does a product not appear in my bundle?
Because the grid shows other products than you expect. Check these:
- Select products has products: it overrides Select collection, so only the picked products show.
- Maximum number of products shown is lower than the number of products in the collection. Raise it (up to 96).
- The product is not in the collection, or not published to the Online Store sales channel.
Why do the set and bundle look different on mobile?
Because both sections move their buttons to a bar at the bottom of the screen on mobile. The Products set bar shows the Mobile design Title and Subtitle. The Products bundle panel is a bar that opens and closes; Have discount panel opened by default on mobile. opens it when the page loads.
Related pages
- Discounts and bundles: the setup of sets, bundles and their discounts.
- Products bundle section: all settings of the build-your-own bundle.
- Products set section: all settings of the fixed kit.
- Cart theme settings: the discount code field in the cart.
How do I change the button colors?
How to change button colors in Combine: buttons follow the body text color, the Buy buttons block has its own color, and the rest needs custom CSS.
Troubleshoot popups
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