SKU columns do not match cleanly
Supplier files often contain spaces, case differences, blank SKU rows, or duplicate SKU rows. These should be reported instead of silently merged into the Shopify export.
Workflow guide
Shopify Inventory CSV Update
Use this workflow when the store already has a Shopify inventory export and a second file with current supplier, warehouse, POS, or ERP quantities. The workflow creates a Shopify-ready inventory update CSV and a separate exception report so unmatched SKUs, duplicate SKUs, blank SKUs, and invalid quantities are reviewed before import.
Merge supplier SKU quantities into a Shopify inventory export without overwriting the wrong rows.
Quick checklist
- 1Use the Shopify inventory export as the base file.
- 2Match supplier quantities by SKU, not product title or vendor name.
- 3Review unmatched, duplicate, blank, and invalid quantity rows before import.
Who this workflow is for
Shopify merchants, ecommerce operators, inventory assistants, and VAs updating stock from supplier or POS exports.
- Primary search intent
- shopify inventory csv update
- Best fit
- Merge supplier SKU quantities into a Shopify inventory export without overwriting the wrong rows.
Why this workflow matters
The supplier file has the right stock counts but different column names from Shopify.
Some SKUs exist in Shopify but are missing from the supplier export, or the supplier export contains SKUs not found in Shopify.
Duplicate SKUs or blank SKU rows make a direct spreadsheet merge risky.
The operator needs a clean import file plus an exception report to review with the merchant before importing.
Input files you need
- Shopify inventory CSV export
- Supplier, warehouse, POS, or ERP stock CSV with SKU and quantity columns
Output files and reports
- Shopify inventory update CSV
- Exception report for unmatched, duplicate, blank, or invalid SKU rows
Before you start
- Export the current Shopify inventory CSV before editing quantities.
- Ask the supplier or POS system for a CSV with one SKU column and one current quantity column.
- Decide whether missing supplier SKUs should keep their Shopify quantity or be reviewed manually.
- Do not edit the original exports directly; generate a separate ready file and exception report.
Run the workflow
- 1Export the inventory CSV from Shopify.Open Shopify Inventory CSV Stock Update Builder
- 2Paste the Shopify export and supplier stock CSV into the inventory update builder.
- 3Confirm the SKU and quantity columns.
- 4Download the ready CSV and exception report.
- 5Fix exceptions, then import the ready CSV manually in Shopify.
Common failure points
Quantity values are not import-ready
Negative values, decimals, blank quantities, and text values can make an inventory import unreliable. The workflow treats invalid quantity rows as exceptions.
The update file hides missing supplier data
A stock update can look complete while leaving Shopify SKUs untouched because the supplier file did not contain them. The exception report keeps those missing matches visible.
Use Shopify's export as the base file
The inventory export is the safest base because it already contains Shopify's expected inventory rows. The supplier or POS file should update quantities against that base, not replace the file structure with an unrelated spreadsheet.
- Keep the Shopify export header order intact.
- Match by SKU instead of product title or vendor name.
- Generate a new ready CSV instead of editing the export in place.
Review exceptions before import
The exception report is the operational value of the workflow. It gives the merchant or inventory assistant a smaller list of rows to judge instead of forcing them to scan the full spreadsheet.
- Review unmatched Shopify SKUs before deciding whether stock should stay unchanged.
- Review supplier-only SKUs before adding new products or variants.
- Fix duplicate and blank SKUs in the source file, then re-run the workflow.
Re-run the workflow after fixes
Inventory updates are repeat work. After fixing source rows, run the same check again and keep the latest ready CSV paired with its exception report. That gives the importer a simple audit trail for what changed.
Sample outputs to expect
Shopify inventory update CSV
A Shopify-shaped CSV with updated quantity values merged from the supplier or POS file.
Inventory exception report
A review CSV for unmatched Shopify SKUs, supplier-only SKUs, duplicate SKUs, blank SKUs, and invalid quantities.
Checks performed
- SKU matching between Shopify and supplier files
- Duplicate supplier SKUs and duplicate Shopify SKUs
- Blank SKUs and invalid non-integer stock quantities
- Shopify SKUs not found in supplier file and supplier SKUs not found in Shopify
Limits and boundaries
- Does not connect to the Shopify API.
- Does not import the file into Shopify for you.
- Does not infer business rules for duplicate SKUs or unknown supplier rows.
Tools in this workflow
FAQ
Does this workflow connect to Shopify?
No. It works with pasted CSV data in the browser and creates files you can review before importing manually in Shopify.
What happens to SKUs that do not match?
They are written to an exception report so the operator can decide whether to fix the source file, add missing variants, or leave those rows unchanged.
Can this update multiple inventory locations?
It can preserve Shopify-shaped inventory rows from the export, but the operator still needs to confirm the correct location and quantity columns before importing.