Margin first
Reject risky discount contexts before they become margin problems.
Guide
How to prevent Shopify discount leakage
Discount leakage happens when a valid promotion applies in a cart where the merchant never intended to discount margin-sensitive items.
Small rule set
Prebuilt guardrails avoid a sprawling discount rules builder.
No cart history
Cart context is evaluated ephemerally and discarded after the decision.
What to do first
Start with the smallest guardrail that prevents the most expensive failure. Add complexity only after the simple rule proves useful.