How to Add New Variants to Existing Products in Shopify Using Stock Sync

This guide explains how to add new variants to products that already exist in your Shopify store using Stock Sync. This is useful when a product was created without all available variants, and you want to merge additional variants later.

Requirements

Before merging new variants into an existing product, ensure the following:

• The Product Identifier (SKU, Handle, Barcode, or metafield) must match an existing product in your Shopify store.
• Each variant must have a unique SKU.
• All variants belonging to the same product must share the same Variant Group value.
• Variant Option fields (Color, Size, etc.) must be mapped correctly.

Steps to Add New Variants to Existing Products

1. Open your Add Product feed in Stock Sync.
2. Go to Edit Settings → Step 2 → Smart Settings.
3. Turn ON Merge variants into existing products.
4. Under Variant Group, map the field that groups variants together (such as Product Title, Handle, Old Code, or another shared value).
5. Map your Variant Options (e.g., Size, Color) to the matching columns in your file.
6. Ensure the Product Identifier is mapped to a value that already exists in Shopify.
7. Run the Add feed.

Notes

• If the Product Identifier is already in your store and does not match the grouping value, variants will not merge.
• If the existing product title in Shopify does not match the feed title exactly, the merge may fail.
• If variants fail to appear, check that the new variants do not reuse an SKU already assigned to a different variant.

Common Issues

• Variants not merging due to mismatched titles.
• Product Identifier mapped to a value that already exists but belongs to a different product.
• Missing Variant Group value.

Example

If you have a product with existing variants S and M, and later want to add L:

• Ensure all three variants share the same Variant Group (e.g., "Shirt-123").
• Map variant option Size to S, M, L.
• Run the Add feed with "Merge variants into existing products" enabled.

The system will attach the new L variant to the existing product instead of creating a new product.

If you encounter issues, verify your mapping setup or share sample SKU data with support for review.

Updated on: 14/07/2026