They’d use Compare at Price for a sale, and Shopify would still allow customers to apply discount codes on top. No native way to block this. Deleting codes or hiding the field doesn’t actually stop discounts.
So I built an app that blocks discount codes when products are already discounted, especially during sales.
It:
Prevents double discounts on Compare at Price products
Blocks codes at checkout logic level (not just UI)
Can be scheduled for sales like Black Friday