Discount Stacking Limitations: Inability to Combine Multiple Discount Codes and Automatic Discounts

Technical Q&A

Topic summary

Shopify enforces strict limitations on discount stacking at checkout, preventing merchants from combining multiple promotional offers:

Key Restrictions:

  • Only one discount code allowed per checkout
  • Automatic discounts and discount codes are mutually exclusive—applying one removes the other
  • Buy X Get Y (BXGY) promotions cannot stack with other BXGY offers or discount codes
  • Free shipping discounts cannot combine with other codes
  • Line item discounts can combine with cart-level discounts only when not applied via discount code (limited to flat/percentage types)

Business Impact:

  • Merchants cannot run simultaneous promotions (e.g., sitewide sale + free shipping code)
  • App developers face constraints building flexible promotional tools
  • Customer frustration when expected discount combinations fail

This remains an open platform limitation with no resolution indicated.

Summarized with AI on October 26. AI used: claude-sonnet-4-5-20250929.
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Issue Summary:
Shopify currently blocks stacking (combining) certain types of discounts at checkout. This limitation impacts both merchants and app developers who want to offer more flexible promotions to their customers.

Details:

  • Only one discount code can be applied per checkout/cart.
  • Automatic discounts cannot be combined with discount codes. If a discount code is entered, the automatic discount is removed, and vice versa.
  • Buy X Get Y (BXGY) discounts cannot be combined with other BXGY discounts or with discount codes.
  • Free shipping discounts cannot be combined with other discount codes.
  • Line item discounts (applied directly to a product or variant) can be combined with a cart-level discount, but only if the line item discount is not itself a discount code. Line item discounts support only flat or percentage discounts, not codes.

Impact:

  • Merchants are unable to run multiple promotions simultaneously (e.g., a sitewide discount code plus a free shipping code).
  • App developers are limited in the types of promotional experiences they can build for merchants.
  • Customers may be frustrated when they cannot combine offers as expected.

References:

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