Shopify Discount Combinations: Stacking Bundles and Codes

Shopify discount combinations let more than one discount apply to the same order. The catch: each discount has to allow the other one. A bundle discount and a welcome code only stack when both are set to combine with each other’s class. If they can’t combine, Shopify picks the better deal for the customer.

This guide covers which discounts can stack, how Shopify does the math, and how to set rules for bundle offers and codes before a sale. For the bigger picture on bundle types, see our product bundles guide.

What are Shopify discount combinations?

Every Shopify discount belongs to a class. The class decides what it applies to and what it can stack with. Shopify lists three (Shopify Help Center):

When you create a discount, its Combinations section asks which classes it can combine with. That works for both automatic discounts and discount codes.

The setting has to match on both sides. Shopify says multiple discounts apply “only when the setting on each discount allows the combination”. So a code that allows product discounts won’t stack with a bundle offer that doesn’t allow order discounts.

Which discounts can you stack on Shopify?

Shopify lists six types of combination, and one pairing that never works. Not every store gets all six:

“Eligible” means your store doesn’t use checkout.liquid customizations and doesn’t use the Licensify app. Same-item product stacking on Plus also needs matching tags on both discounts.

A few limits matter during big sales:

• 25 active automatic discounts at most. That count includes app discounts.
• 5 product or order codes and 1 shipping code per order.
• Online Store, Storefront API and Shopify POS only. Combinations aren’t available on external checkouts such as Facebook, Instagram or Google.
• Native Buy X get Y items don’t take more product discounts on plans below Plus. A product code on those items means the customer gets whichever deal is better overall.

How does Shopify calculate stacked discounts?

Shopify applies discounts in a fixed order:

1. Product discounts apply first, to individual items.
2. Order discounts apply to the new subtotal, after product discounts.
3. Shipping discounts apply last.

That order changes the math. A product discount followed by an order discount multiplies. Two percentage order discounts add up, because Shopify calculates both on the same subtotal.

Here is an example with made-up numbers on a $100 cart:

The 30% row comes straight from Shopify’s own example. The takeaway: two order codes stack harder than a bundle plus a code. Run every stack you allow through your margin numbers. Our bulk discount margin math post shows how to find your break-even discount.

What happens when discounts can’t combine?

Shopify says that when discounts can’t be combined, “the best discount for the customer’s cart is always applied”. So nothing breaks. The customer just gets one deal, not both.

If a customer enters two codes that can’t stack, checkout shows: “Discount couldn’t be used with your existing discounts.”

How do you combine discount codes in Shopify?

You set combinations on each discount, in the Shopify admin:

1. Go to Discounts and open the discount, or create a new one.
2. Find the Combinations section.
3. Tick the classes it can combine with: product, order or shipping discounts.
4. Click Save.
5. Repeat for the other discount, so both sides allow each other.

You don’t need to set up both at once. Save the first discount, then create the second. Once both allow each other, they combine on their own when a customer qualifies.

To audit what you have, go to Discounts, add the Combines with filter, and pick the classes you want to see. Editing a discount to allow combinations doesn’t change orders that already used it.

Shopify also suggests naming codes so staff know what they do, for example STACK10-SHIPPING.

How do bundle offers stack with discount codes?

A bundle app discount follows the same rules as any other discount. It has a class, and it needs combination settings that match your codes.

In Sam Bundles, quantity breaks and buy X get Y offers run as an automatic Shopify product discount, so customers don’t enter a code. Fixed bundles, mix and match and bundle builder offers get their prices through Shopify’s Cart Transform. Each offer has its own stacking rules.

Set combinations on a Sam Bundles offer

1. Open the offer and scroll to the Advanced card.
2. Under Discount combinations, tick Product discounts, Order discounts or Shipping discounts.
3. Under Customer eligibility, choose All customers, Logged-in customers, Non logged-in customers or customers with specific Customer tags.
4. Save the offer.
5. Open your discount code in the Shopify admin and allow product discounts in its Combinations section.

New offers start with Product discounts ticked and the other two unticked. That means a free shipping code or an order code won’t stack with the offer until you tick those boxes. The offer settings guide shows the card.

Which boxes should you tick?

It depends on the promo. Here is a starting point:

The goal is a rule you chose on purpose, not one you find out about from a support ticket. For BOGO margins in detail, see how to set up buy one get one free.

Why won’t my Shopify discounts combine?

Most stacking problems come down to a few causes. Shopify’s troubleshooting list covers them:

• Only one side allows it. Open both discounts and check the Combinations section on each.
• Another automatic discount wins. An active automatic discount might conflict with the code. Review what’s live.
• You hit a limit. Check the 25 automatic discounts cap and the 5 code limit.
• The items don’t qualify. If a product doesn’t meet one discount’s rules, the combination might not work.
• Two product discounts on one item. Below Plus, Shopify keeps the better one.
• Shipping loses to product or order discounts. If they can’t combine, customers may see “You already have a better combination”. Shopify gives product and order discounts priority, because the cart value affects shipping rates.
• Option missing. If you can’t combine product and order discounts, check checkout.liquid and app compatibility.

Shopify also notes that Scripts and some checkout apps can reject codes. Turn them off one at a time to find the cause.

How do you test discount combinations before a sale?

Test with the cart and checkout, before you announce anything. You can stop before payment.

1. Add a bundle or quantity break to the cart. Confirm the bundle price shows.
2. Enter your discount code. Check that it stacks, or doesn’t, as you planned.
3. Add a free shipping code. Check it applies on top, if you allowed it.
4. Try a product that’s excluded from one of the discounts. The total should still make sense.
5. Try two order codes together. Check the total matches the “add up” math.
6. Log in as a tagged customer if you used Customer tags.
7. Write the final price down and compare it with your break-even.

Test again after any change to a discount. For more on choosing the bundle discount itself, read our bundle pricing strategy guide. If you are weighing Shopify’s free Bundles app against a bundle app, see Shopify Bundles app vs a bundle app.