Multiple Fixed Discount Codes for One Product

Topic summary

A merchant is issuing multiple discount codes as store credit for event wins and wants to know if customers can combine/stack these codes at checkout.

Current Shopify Limitations:

  • Shopify only allows discount combinations under specific conditions
  • To stack discounts, one must be a product discount and the other an order discount
  • Multiple codes of the same type cannot be combined natively

Potential Solutions:

  • Third-party apps exist but often rely on workarounds that can be unstable and cause compatibility issues
  • Shopify has a new Discount Allocator Functions API in developer preview that will allow custom discount combination rules
  • This API is not yet available to all stores and will likely take time before general release

Recommendation:
Monitor updates to the Discount Allocator Functions API for a more robust future solution, as current workarounds may be unreliable.

Summarized with AI on November 9. AI used: claude-sonnet-4-5-20250929.

We give our store credit per win and per event.

We are generating multiple discount codes for accountability.

Is there anyway customers can stack these codes together in checkout? I’ve clicked that they can be combined with the other coupons but Shopify only allows one.

Shopify support discount combinations at some point.

Here’s the link to the helpdesk article that explains the rules for combinations:

https://help.shopify.com/en/manual/discounts/combining-discounts/discount-combinations

If you 2 want discounts to “stack,” then one must be a product discount, and the other must be an order discount.

You could try a 3rd party app, but apps that let you circumvent Shopify’s restrictions are usually built on workarounds, and therefore are brittle and cause compatibility issues when Shopify releases new APIs.

Shopify has a new API in the developer preview that will let you set custom discount combination rules for your store, called the Discount Allocator Functions API:

https://shopify.dev/docs/api/functions/reference/discounts-allocator

It will probably be a long time before this is available to all stores, but I’ve got my eye on this, and I recommend you stay tuned for updates about that API as well.

Best,

Tobe