Updating package details across a large Shopify catalog is risky when the source spreadsheet mixes product IDs, dimensions, weights, and package assignments.
The first important distinction: Shopify's normal product CSV workflow is not a universal package-management importer. Treat your CSV as a planning and validation layer, then apply the reviewed data through Shopify admin or an approved API/app workflow.
1. Use stable product identity
Include at least one reliable identifier for every assignment:
Handle
