A merchant encountered an issue where a customer ordered two units of the same cosmetic set SKU, but the order displayed them as three separate line items instead of consolidating them. This caused confusion as the warehouse system only recognized one product needing shipment.
Root Cause:
The duplication occurs when post-purchase upsell apps add items at checkout
Buy-one-get-one (BOGO) discounts can trigger the same behavior
Shopify creates separate line items rather than consolidating identical SKUs in these scenarios
Recommended Solution:
The warehouse integration system needs to be configured to recognize and sum multiple line items sharing the same SKU to determine the correct total quantity for fulfillment.
Unresolved Questions:
Whether Shopify Flow can automatically consolidate duplicate SKUs remains unanswered
No confirmed workaround has been shared by participants
Summarized with AI on November 2.
AI used: claude-sonnet-4-5-20250929.
I have situation when my customer purchased two of my cosmetics set (one SKU), but it displayed it like two seperate products.
Since I have only one of this product made in the system I don’t know how it doubled, but warehouse got information that the only one product needs to be sent.
The second item was added by the post-purchase upsell app configured at checkout. When a second item with the same SKU is added, it adds another line item, it does not consolidate the line items. That is why you see 3 line items with a count of 1 in the order details. Buy one get one discounts can also cause this to happen. Your warehouse integration needs to be aware of and account for multiple line items with the same SKU.