Troubleshooting
Overlapping rules — only one discount applies
When multiple active rules target the same variant, what happens at checkout.
If you have multiple active rules and they target some of the same variants, only one will apply at checkout per matched variant — unless you've explicitly enabled combinations.
How Shopify decides which one wins
When multiple non-combinable discounts could apply to the same item, Shopify picks the one that gives the largest discount to the customer. This isn't configurable.
So if Rule A is 20% off and Rule B is 30% off, and both target a variant the customer adds to cart, Rule B wins.
How to spot overlap
The Home page shows an alert when overlap is detected:
"X variants are targeted by multiple active rules — only one discount will apply"
Click Review to see which rules are overlapping. Use the Browse modal on each rule to see exactly which variants are shared.
How to resolve overlap
Three options:
1. Enable combinations
If you actually want the rules to stack (rare), enable "Combines with other product discounts" on both rules. They'll both apply at checkout. See Discount combinations.
2. Tighten the conditions
Make each rule's conditions more specific so they don't overlap. Example:
- Original: Rule A targets
Tag is "summer", Rule B targetsCollection is "Summer 2026"(overlap because most summer-tagged items are in the Summer collection) - Resolved: Rule A becomes
Tag is "summer" AND Tag is not "main-summer-promo"to exclude Rule B's items
3. Switch one to code-based
If the rules are running for different reasons (e.g. a sitewide automatic + a targeted email-list discount), make the targeted one code-based. It only applies when customers enter the code, eliminating accidental overlap with the automatic one.
Active period conflicts
If two rules have overlapping schedules AND target overlapping variants, the rule editor warns you when you try to save. The warning gives options:
- Remove the date range from one rule
- Change the dates to avoid overlap
- Switch one to code-based
You can save anyway and let the larger-discount-wins logic decide, but the warning helps you make an intentional choice.
Inactive rules don't overlap
Only Active rules can conflict. Saved-but-inactive rules don't affect anything until activated. You can have many inactive rules with overlapping logic (e.g. variants of a future promotion) without any checkout impact.