Discount Prime runs automatic discounts alongside Shopify's own discounts, product discounts, order discounts, and shipping discounts and lets you control how they combine (stack) at checkout. Instead of a customer only ever getting one discount, you decide whether your campaigns stack with each other and with Shopify discount codes, so shoppers get the best possible deal without any manual work at checkout.

Every campaign applies automatically once it's live. The combination setting on each campaign is what determines whether two discounts add up on the same cart or whether only the strongest one wins.

Discount Prime uses Shopify's native discount classes, so combinations follow Shopify's own rules:

- Product class: Flat Product Discount, Tiered Quantity, Bulk Price Update, Tiered Unit Pricing

- Order class: Tiered Spend Discount, Product Spend Discount

- Shipping class: Free Shipping & Cart Incentives

Discounts from different classes can stack (e.g. a Product discount + a Shipping discount). Whether discounts from the same class stack, or from a Shopify discount code, depends on each campaign's combination setting.

- Can combine: both discounts stack, the customer gets both

- Cannot combine: only the highest-value discount wins (MAX logic)

- Volume discount + free shipping over a threshold: Product/Order campaign + Free Shipping campaign (different classes, stack automatically)

- Let a seasonal promo stack with a coupon code: turn Can combine ON so your campaign stacks with Shopify discount codes

- Prevent double-dipping on the same products: turn Cannot combine ON so only the best discount applies

- Reward big carts with a stacked deal: Tiered Spend Discount + Free Shipping, both set to combine

Scenario Used in This Guide

Goal: Run a 20% volume discount on selected products AND give free shipping when the cart reaches $50, both applying together, automatically, at checkout.

Step 1: Create the Product Discount Campaign

From the Discount Prime sidebar, click Campaigns → Create Campaign and set up your product/volume discount (e.g. Tiered Quantity Discount or Flat Product Discount).

In the Combination section of the campaign, choose whether it can combine with other same-class or coded discounts:

- Can combine: stacks with other product discounts / codes

- Cannot combine: only the highest discount wins

Save the campaign.

Step 2: Create the Free Shipping Campaign

Create a second campaign of type Free Shipping & Cart Incentives, with a minimum spend of $50 and discount Free Shipping (100%).

Because Shipping is a different class from Product, this shipping discount stacks with your product discount automatically.

Step 3: Check the Combination Setting

Open the campaign's Combination Setting and make sure it's allowed to combine with product/order discounts running at the same time.

IMPORTANT: If the combination option is not checked, the discounts may apply exclusively (only one wins). To let multiple discounts apply together, the combination option must be enabled.

Step 4: Mind the Execution Order (Advanced)

Under Advanced Settings, the shipping campaign's minimum check can run:

- Before: checks the cart subtotal before product discounts are applied

- After: checks the subtotal after product discounts are applied

If your 20% product discount would drop the cart below $50, choose Before so the product discount doesn't cost the customer their free shipping.

Step 5: Save

Both campaigns are now live and will apply together whenever a cart qualifies. No further action is needed.

Test Scenario

Product discount: 20% off selected products

Shipping: Free shipping over $50

Store shipping rates: Standard $8.99, Express $18.99

Verification Table

- $30 of discounted products: product discount applied, full shipping rate (below $50 threshold)

- $60 of discounted products: product discount applied, shipping $0.00 (both discounts stack)

- $60, product discount set to Cannot combine with a code: only the higher of the two applies, shipping $0.00 (same-class MAX logic)

Step 1: Add Below Threshold

Add $30 of discounted products in an Incognito tab. At checkout, confirm the product discount applies but shipping is still full price.

Step 2: Cross the Threshold

Add products until the cart reaches $60. Go to checkout after entering the shipping address.

You should see both:

- The product discount line (−20%)

- Shipping showing $0.00 for all rates

Step 3: Test a Non-Combining Case

Set the product campaign to Cannot combine and add a Shopify discount code at checkout. Confirm only the highest discount is applied, not both.

TIPS & COMMON MISTAKES

- Combination must be checked. The single most common mistake: leaving the combination option off, so discounts apply exclusively instead of stacking. If a customer isn't getting both, check this first.

- Same class vs. different class. Product + Shipping stacks naturally (different classes). Product + Product only stacks if Can combine is ON.

- Execution order changes qualifying spend. With After mode, a product discount that lowers the cart below the shipping threshold will also remove free shipping. Use Before to protect the threshold.

- Codes follow the campaign. Whether a Shopify discount code stacks with your automatic campaign is governed by the campaign's combination setting, not by the code itself.

- No technical setup needed. Once campaigns are saved, the app manages all combinations in the background, no checkout scripts or manual adjustments.