The Duplicate SKU Sync app updates inventory across all products that share the same SKU. While this process is typically very fast, there is a small delay between receiving an order and completing the inventory update for every duplicate SKU.
During this short synchronization window, there is a rare possibility of incorrect inventory updates if another order for the same SKU is placed before the first sync has finished.
How It Happens
Consider the following example:
- Product SKU ABC has an available inventory of 57 units.
- Customer places Order #1001 for 2 units.
- The remaining inventory becomes 55 units.
- The app begins updating all products sharing SKU ABC to 55 units.
- This synchronization may take a few seconds (or, in some cases, a couple of minutes), depending on the number of products and Shopify API processing.
- Before the update is completed, another customer places Order #1002 for the same SKU ABC.
- Because the previous inventory update is still in progress, there is a small chance that the second order could be processed using outdated inventory values, resulting in an incorrect inventory sync.
Why Does This Happen?
This limitation exists because Shopify inventory updates are processed through APIs and cannot always be completed instantly, especially when:
- A large number of products share the same SKU.
- Multiple orders are placed within a very short period.
- Shopify API rate limits delay inventory updates.
Important Notes
- This is a rare edge case that only occurs when multiple orders for the same duplicated SKU are placed almost simultaneously.
- Once the inventory synchronization is complete, all products sharing the SKU will have the correct inventory value.
- During the brief synchronization window, there is a possibility of temporary inventory inconsistencies.
Tip: This scenario is uncommon and typically affects stores with high order volumes or products that experience multiple purchases within seconds.