Discount Validation Extension at Checkout
What is the Discount Validation Extension?
The Discount Validation Extension is a checkout extension that helps you control how and when discount codes are applied. While Shopify already validates basic discount rules (like minimum items, order value, or product-specific codes), the extension allows you to:
Add custom rules that Shopify doesn’t support by default.
Ensure discounts remain valid even if customers edit orders after checkout.
Provide a consistent experience across checkout, thank-you page, and order edits.
Why is it needed if Shopify already checks discounts?
Shopify by itself will:
✅ Reject codes that don’t exist.
✅ Apply rules you set in Shopify Discounts (e.g., min 2 items, min $50 order).
❌ But Shopify won’t check advanced conditions like:
Only allow discount for customers with a specific tag (e.g., VIP).
Restrict discounts by shipping method or country.
Make sure discounts are still valid if the order is edited post-purchase.
This is where the Discount Validation Extension adds value.
How does it work?
Add the extension → Go to Shopify Admin block.
→ Settings
→ Checkout → Customize
→and add the Discount Validation
At checkout, when a customer enters a discount code:
Shopify checks the basic validity.
Account Editor runs your custom rules on top.
If rules don’t match, the discount is rejected.
Example
Let’s say you create a discount code: VIP20
Shopify Rules → Code exists, valid for 20% off.
Account Editor Rule → Only customers with the tag VIP can use it.
👉 At checkout:
If a regular customer tries to apply VIP20 → ❌ Rejected.
If a VIP customer applies VIP20 → ✅ Accepted.
What happens after checkout?
If the order is edited later (e.g., items removed, shipping changed), Account Editor will re-validate the discount.
Example: Code requires 2 products.
Customer checks out with 2 shirts, discount applies. Later they edit the order and remove 1 shirt.
Shopify won’t re-check → discount stays (wrong).
Account Editor re-checks → discount removed (correct).
Best Practices
Always keep “Enable Discount Recalculation” checked in Account Editor settings to make sure discounts update after edits.
Use Shopify’s built-in discount rules for basic conditions (min spend, products, quantity).
Use Account Editor Discount Validation for advanced or custom conditions.
Test with a simple scenario: set a condition (e.g., “Cart value ≥ $50”) and apply the discount with a smaller cart to see it in action.
Summary
Shopify validates basic discount rules.
The Discount Validation Extension lets you add custom rules and ensures discounts remain fair after edits.
Simple setup: add the block at checkout + configure conditions in Account Editor.
Example: “VIP20” only works for VIP-tagged customers.
With this, you can give customers a smooth checkout experience while protecting your business from misused discounts.