Discount not applying at checkout
The bundle adds to cart, but the box discount isn't taken off.
Bundle discounts are applied by Shopify's automatic discount function at checkout, not in the cart. Always judge it by the checkout total.
1. Does the selected box have a discount?
Open the builder, go to the Products tab, and check the Quantity as an option card. A box set to No Discount is working correctly when nothing comes off.
2. Did the customer complete the box?
The discount belongs to a box size. If your builder requires 10 items and only 8 were added, the box isn't complete — check your selection rules and box quantities line up.
3. Is another automatic discount taking over?
Go to Shopify admin → Discounts.
Look for other automatic discounts covering the same products.
Pause the conflicting one and retest.
Two automatic discounts competing over the same line items is the most common cause.
4. Check discount combinations
Each Shopify discount has combination settings. If the bundle discount can't combine with an active order or shipping discount, it gets dropped. Review those settings on the other discount.
5. Is the bundle's parent product missing?
If you see the banner This bundle's parent product was deleted, the hidden product that represents the bundle in the cart is gone. Save the builder again to recreate it.
6. Multi-currency stores
Confirm your currency rates in Settings → Markets. A wrong rate makes a correctly applied discount look wrong.
Test with a real order
Previews and draft orders don't exercise the discount function the same way. Place a small live test order — you can refund it — to confirm end to end.