Cleaning Supplier CSVs for Shopify Import
Published
Supplier spreadsheets are written for the supplier's system, not your store. Importing one directly is how catalogs end up with duplicate products, missing variants and prices that are really costs. A little preparation prevents all three.
1. Export a backup first
Before changing anything, export your current products from the Shopify admin and keep the file somewhere safe. A bulk import can overwrite a great deal in a few seconds. The export is your undo button.
2. Start from Shopify's own template
Download the sample product CSV from Shopify's help center and use its column headers exactly as written. Do not rely on headers remembered from an older file or copied from a tutorial, because the expected format can change. If a header does not match, the column is ignored or the import fails.
3. Map the supplier's columns once, in writing
Make a simple two-column table: the supplier's field on the left, the Shopify field on the right. Note any transformation needed, such as converting units, combining two columns into a title, or turning a category code into a product type.
Writing the mapping down is what makes the next file quick. The supplier will send an update, and you do not want to work it out again from memory.
4. Get variants right
In a Shopify product CSV, variants of the same product share one handle. Each variant is its own row, and the handle is what tells Shopify the rows belong together.
- Supplier files often list every size and color as a separate product. Group them under one handle.
- Keep option names consistent. "Colour" on one row and "Color" on the next creates two different options.
- Give every variant a unique SKU. It is the most reliable way to match rows on later updates.
5. Apply pricing rules, do not type prices
Supplier files usually contain your cost. Your selling price should come from a rule: a markup, a rounding convention and, if you use them, a compare-at price. Apply the rule with a formula so every product is treated the same way and the rule can be changed in one place.
6. Clean the text
- Remove stray spaces, line breaks and odd characters left over from the supplier's system.
- Save the file as UTF-8 so accented letters and symbols survive.
- Check that long numbers such as barcodes have not been turned into scientific notation by the spreadsheet program.
7. Test with a small batch
Import ten products before importing ten thousand. Then look at them on the storefront, not just in the admin: titles, images, variant selectors and prices. Errors are much cheaper to find at this stage.
8. For updates, include only what should change
When a later file updates prices or stock, leave out the columns you are not changing. A column full of blank cells can overwrite data you meant to keep.
Once the rules are written down, the routine can be handed to someone else. Processing supplier updates is a common first task for an assistant; see what to delegate to an e-commerce VA first.
If your catalog is large or your supplier files are especially untidy, our Shopify catalog management service handles this end to end.