The Duplicate SKU Sync app keeps inventory synchronized across products that share the same SKU. However, there is a known Shopify limitation that can affect inventory synchronization when using the Shopify Transfers feature.
Understanding this limitation will help you avoid unexpected inventory discrepancies.
Shopify Transfer Limitation
Duplicate SKU Sync relies on Shopify webhooks to detect inventory changes and automatically synchronize duplicate SKUs.
However, Shopify does not currently trigger inventory webhooks when stock is moved between locations using the Shopify Transfers feature.
Because no webhook is sent, the app is not notified that the inventory has changed.
Note: This behavior is a limitation of Shopify's platform. We have reported the issue to Shopify and requested support for inventory transfer webhooks.
Impact
When inventory is transferred between Shopify locations:
- Shopify updates the inventory correctly in your admin.
- Duplicate SKU Sync does not receive a webhook notification.
- Inventory synchronization is not triggered.
- Products sharing the same SKU may temporarily display different inventory levels.
Example
Suppose you have two products that share the same SKU SKU-123:
- Product A stocked at Location A
- Product B stocked at Location B
You transfer 10 units of SKU-123 from Location A to Location B using Shopify Transfers.
What Happens?
- Shopify updates the inventory quantities for both locations.
- Shopify does not send an inventory webhook.
- Duplicate SKU Sync is unaware of the transfer.
- The duplicate products remain out of sync until another supported inventory update occurs.
Recommended Workaround
To keep duplicate SKUs synchronized after using Shopify Transfers:
- Open the Duplicate SKU Sync app.
- Navigate to the Detailed View section.
- Manually update or resync the affected SKU(s).
This ensures all products sharing the same SKU display the correct inventory levels.
Important Notes
- This limitation only affects inventory changes made using Shopify Transfers.
- Inventory updates made through supported Shopify inventory actions continue to synchronize normally.
- We are actively monitoring Shopify for updates and will support transfer-based synchronization if Shopify makes the required webhook available in the future.