Keep overlapping discounts clear
Buy 2 get 1 free, free shipping, and a VIP code should not turn into a confusing cart. This guide explains how Atom Discounts keeps discount behavior predictable when offers overlap.
Why this matters
The value is simple: shoppers should understand the deal, and your team should know which discount will apply before a campaign goes live.
Atom Commerce uses a clear evaluation order so discounts do not pile up unpredictably or erase margin by accident.
Evaluation order
Priority Within Each Class
Within each offer class, higher-priority offers evaluate first. This ensures the most important discounts take precedence.
Key Rules
- One item-level discount per product line: Only the highest-priority item discount applies
- Order-level evaluates on post-item subtotal: After item discounts are applied
- Shipping-level evaluates last: After both item and order discounts
Stacking Rules
Stacking determines which offer classes can combine together. This prevents margin erosion while allowing strategic combinations.
Common Stacking Patterns
Item + Order (Recommended)
Volume discount + order threshold discount
Item + Shipping (Recommended)
Product discount + free shipping threshold
Order + Shipping (Recommended)
Order discount + shipping discount
Example Scenarios
Scenario 1: Volume + Order Threshold
Setup: 10% off collection A (item-level, priority 90) + 10% off orders $140+ (order-level, priority 80)
Cart: $150 in collection A products
Result: Item discount fires first → subtotal becomes $135 → order-level no longer qualifies
Scenario 2: Clean Stacking
Setup: 15% off collection A (item-level, priority 90) + Free shipping $75+ (shipping-level, priority 80)
Cart: $100 in collection A products + $10 shipping
Result: Item discount → $85 subtotal → Free shipping applies → Final total: $85
Best Practices
- Set clear priorities: Use distinct priority numbers (90, 80, 70) to avoid conflicts
- Test boundary cases: Try carts just below and above thresholds
- Use combinations intentionally: Allow stacking only where it adds value
- Document your rules: Keep a simple table of active offers and their settings
- Set end dates: Prevent legacy promotions from interfering with new campaigns
Common Questions
How does Atom Discounts evaluate Shopify discounts?
Atom Discounts evaluates item-level offers first, then order-level offers, and finally shipping-level offers so discount outcomes stay predictable.
Can Shopify item-level and order-level discounts stack in Atom Discounts?
Yes, when combinations are allowed. Item-level offers evaluate before order-level offers, so the order-level minimum is checked against the post-item-discount subtotal.
Why is offer priority important for Shopify discounts?
Priority determines which discount evaluates first within the same class, which helps teams prevent accidental double-discounting and choose the intended winning offer.
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