Shopify has two important rules to keep in mind when it comes to combining discounts.

1. Discounts only combine if both allow it

Two or more discounts can only be stacked when each one is set to combine with the other’s type.

Think of it as a two-way handshake:

• Discount A must allow combining with Discount B.

• Discount B must allow combining with Discount A.

Example: Product + Shipping Discounts

If you want to let customers use a Product discount (the discount type EG uses to make the items it adds discounted) and a Shipping discount (e.g. free delivery) together:

• The Product discount must be enabled to combine with Shipping discounts.

• The Shipping discount must be enabled to combine with Product discounts.

2. When two discounts apply to the same item

If more than one discount is eligible for the same product or line item, Shopify will automatically apply the one that gives the customer the biggest saving.

Example:

• A product is eligible for 20% off and also $10 off.

• Shopify compares them and applies whichever reduces the price more.

This ensures customers always get the best deal, even if multiple discounts are available.