How do I fix "Seller sku id is duplicate" errors when I try to add a new product to Lazada?

This error happens because Lazada does not allow variants with the same SKU. Every variant on Lazada must use a unique Seller SKU and if you are using a Seller SKU for an existing variant on Lazada you cannot use the same Seller SKU on a new Variant.

For example, let's say you already have a product on Lazada:

Lazada Product: "Red T Shirt" with 2 Seller SKUs "red-large", "red-xlarge"

You want to add a Shopify Product to Lazada:

Shopify Product: "Red Dress" with 2 Seller SKUs "red-large", "red-small"

Lazada will not let you add "Red Dress" to Lazada because you are already using "red-large" as a Seller SKU on an existing Lazada Product.

How Do I Fix This?

You can fix this by:

1. Using a different SKU on the product you are trying to add, or
2. Logging into Lazada and deleting the product with the same SKU

For example, this product on Shopify has a SKU "strawberry-default".

But on Lazada there is already a product with the same SKU "strawberry-default"!

If you try to use to the app to add the Shopify product to Lazada, Lazada will not allow the the app from adding the new product because the new product has the same SKU "strawberry-default".