Guardrail: Discount Conflicts

When to use this guardrail

Run these checks before creating or updating any discount — whether automatic discount rule or coupon. Discount conflicts are one of the most common merchant mistakes — overlapping discounts silently stack and give customers a much deeper discount than intended. This is especially dangerous when automatic discounts and coupons interact, since merchants often forget that both mechanisms apply simultaneously.

Check 1: Existing active discount rules on the same scope

Why: Wix eCommerce stacks automatic discount rules. If a 20% catalog-wide discount and a 15% collection discount both apply to the same product, the customer may get both applied.

How to check:

1. Query all active discount rules:

Endpoint: POST https://www.wixapis.com/ecom/v1/discount-rules/query

Request:

2. For each existing active rule, compare its scope against the new rule:

   • If both target CATALOG scope: conflict — both apply to all products
   • If new rule targets CATALOG and existing targets COLLECTION: conflict — catalog-wide includes that collection
   • If both target the same COLLECTION ID: conflict — same products affected
   • If both target the same SPECIFIC_PRODUCTS ID: conflict — same product

3. If a conflict is found, warn the merchant:

   "There's already an active discount '{existingRuleName}' ({existingDiscount}%) that applies to the same products. Adding this new {newDiscount}% discount may stack, giving customers a combined discount. Would you like to deactivate the existing rule first, or proceed with both?"

Check 2: Discount percentage sanity

Why: A discount above 50% is unusual and may indicate a typo (the merchant meant 15% not 50%). A discount of 100% makes the product free.

Rules:

• Discount > 50%: Warn — "This discount is {percentage}% off. Are you sure? This means a $100 product would sell for ${100 - percentage}."
• Discount = 100%: Block unless explicitly confirmed — "This would make the product free. Please confirm this is intentional."
• Discount > 100%: Block — "A discount cannot exceed 100%."

Check 3: Time overlap with existing promotions

Why: Two promotions running simultaneously on overlapping products cause stacking during the overlap period.

How to check:

1. For the new rule's activeTimeInfo (start/end), check if any existing active rule has an overlapping time window on the same scope.
2. Overlap exists when: existingStart < newEnd AND existingEnd > newStart
3. If overlap found on the same scope: warn the merchant about the overlap period.

Check 4: Cross-mechanism stacking (Automatic + Coupon)

Why: Automatic discounts and coupons stack with each other at checkout. A customer with a 20% coupon buying during a 20% automatic sale gets both applied — the effective discount is much deeper than either one alone. This is the most commonly overlooked stacking issue.

How to check:

1. If you are creating an automatic discount: Query active coupons that target overlapping products/collections.
2. If you are creating a coupon: Query active automatic discount rules that target overlapping products/collections.
3. If overlap found, warn the merchant with the combined impact:

   "You have an active {automatic discount / coupon} '{name}' ({X}% off) that applies to the same products. If you create this {coupon / automatic discount}, customers will get BOTH discounts — a combined effective discount of approximately {combined}%. Is this intentional?"

Key rule: Only one coupon can be used per checkout, but automatic discounts have no such limit. The worst case is: multiple automatic discounts + one coupon all stacking on the same product.

Check 5: Minimum profit margin

Why: Deep discounts on low-margin products can result in selling at a loss.

Rules:

• If the merchant has provided cost/margin information, verify that the discount doesn't reduce the price below cost
• If no cost information is available, warn for discounts > 40% as a general safety threshold

Summary: Decision matrix

References

• Discount Rules API (Automatic Discounts)
• Coupons API