The Duplicate SKU Sync app is designed to keep inventory synchronized across products that share the same SKU. However, there are a few edge cases where inventory synchronization may be temporarily inaccurate due to the way Shopify processes orders and inventory updates.

1. Orders Containing Multiple Products with the Same SKU

When a single Shopify order contains multiple products that share the same SKU, inventory synchronization may not always update every duplicate product immediately.

This happens because multiple line items referencing the same SKU are processed within a single transaction, which can occasionally delay or affect the synchronization process.

Example

Suppose the following products all share SKU ABC:

• Product A
• Product B

A customer places one order containing:

• Product A × 2
• Product B × 3

Since both products share the same SKU, the inventory deduction occurs for the combined quantity. In rare cases, the inventory update across all duplicate products may be temporarily delayed, resulting in a short-lived inventory mismatch.

2. High-Frequency Orders for the Same Duplicate SKU

If multiple orders for the same duplicated SKU are placed within a very short period, the app may not complete one synchronization before the next order is processed.

Although inventory updates usually complete within a few seconds, rapid consecutive orders can occasionally result in temporary inventory discrepancies.

Example

1. Order #1001 is placed for 2 units of SKU ABC.
2. The available inventory is reduced to 55 units.
3. Duplicate SKU Sync begins updating all products sharing SKU ABC to 55 units.
4. Before the synchronization finishes, Order #1002 is placed for the same SKU.
5. If the second order is processed before the first synchronization completes, the inventory calculation may use the previous inventory value, resulting in an inaccurate inventory count.

Important Notes

• These scenarios are rare and typically occur only during high-volume ordering or when multiple duplicate SKU products are included in the same order.
• Once synchronization completes, all duplicate products are updated to the correct inventory level.
• The app is optimized to synchronize inventory as quickly as possible, but Shopify API processing times may occasionally introduce short delays.

Tip: To minimize the possibility of inventory discrepancies, avoid maintaining very low stock levels for duplicate SKUs and monitor high-demand products during periods of heavy order activity.