If your product discounts are not stacking as expected, one of the issues below is most likely the cause. Work through each section that matches your situation to resolve it.
1 - The "Combines with other discounts on same cart line" link does not appear
This option is only available on Shopify Plus plans. If your store is on a Basic, Shopify, or Advanced plan, the link will not appear in the discount function editor.
To verify your plan, go to your Shopify admin and navigate to Settings → Plan. If you are not on Shopify Plus, upgrading your plan is required to use this feature.
2 - Discounts are not stacking at checkout
This is the most common issue and is almost always caused by one of the following:
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The tags do not match exactly. Tag names are case-sensitive. Open the Discount settings on both discount functions and confirm the tag is identical on each one — same capitalisation, same spelling, no extra spaces.
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The Product discounts checkbox is not checked on all functions. The Product discounts checkbox under This discount can be combined with must be enabled on every discount function in the group, not only one. Open each function individually and verify.
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The matching tag was not added in the cart-line popup. Adding a tag in Discount settings is only half of the setup. You also need to open the Combines with other discounts on same cart line popup and enter the matching tag in the Discount tags field. If this step was skipped, the combination will not work.
3 - Only one discount is applying — the others are being ignored
Every discount function in the combination group must have both of the following configured:
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The shared tag added in Discount settings → Tags.
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The Product discounts checkbox checked under This discount can be combined with.
If even one function in the group is missing either setting, that discount will not stack. Open each function one by one and verify the full setup before testing again.
4 - The system tags (supaeasy, supaeasy-wizard) are showing in the Tags section
This is expected behaviour. SupaEasy automatically applies four system tags to every discount function: supaeasy, supaeasy-wizard, supaeasy-editor, and supaeasy-api. These cannot be removed or changed, and they do not interfere with your custom combination tags. You can ignore them.
5 - Discounts are combining with the wrong discount
If a discount is stacking with a function you did not intend, it has been assigned the same tag. Open the Discount settings on each affected function, remove the shared tag, and assign a new unique tag to the group you want.
To keep combination groups organised, use descriptive tag names that reflect the promotion — for example, summer-sale-stack or vip-bundle-2026. Generic tag names like combine increase the risk of unintended overlap between discount groups.
6 - Changes are saved but the discount is still not combining
It's rare but can happen that Shopify Functions can take a short time to propagate updates.
After making any changes to tags or combination settings, wait a few minutes before testing at checkout.
If the issue persists after five minutes, try deactivating the discount function and reactivating it.
If you have worked through all of the above and the issue is not resolved, contact the Nextools Support Team via the in-app live chat or by email at: support@nextools.tech.
Include myshopify url, the names of the discount functions involved and a screenshot of the Tags section from each one, this will help the team diagnose the issue faster.
