How do I stop a spreadsheet changing the SKU used to assign product photos?

Why the match breaks

A SKU such as 00127 is an identity value, not a quantity. Spreadsheet software may interpret it as a number and save it as 127, so a photo-assignment process that compares exact SKU text no longer finds the intended product. The same risk applies when an export, copy-paste operation, or CSV re-save changes the value without an obvious warning.

For WooCommerce product media publishing, use the built-in Product CSV Importer and Exporter schema and mapping. Do not substitute instructions for a different extension. The importer must be able to reach each image URL; existing images may be referenced, and the first image in the product’s image list is treated as the featured image.

When an Images cell contains multiple image references, the native schema uses a comma-separated list: enclose the complete CSV cell in double quotes so those commas stay inside one field. The first reference is the featured image. For an update to existing products, select Update existing products and confirm the ID or SKU mapping. Leave unchanged media out of copy-only updates.

Create a small non-destructive fixture

Work from a copy of the product export or a separate test CSV, while preserving the original export and original image files. Use two explicitly different rows so an accidental match is visible: one product has SKU 00127 and image URL ending in blue-mug.jpg; the other has SKU 1270 and image URL ending in red-mug.jpg. These names and values are illustrative exercise data, not a claim about your catalog.

Before any A/B comparison, define the two assets: Asset A is the product identity text 00127 paired with blue-mug.jpg; Asset B is the product identity text 1270 paired with red-mug.jpg. The pass condition is that Asset A remains paired with the first product and Asset B remains paired with the second. A failure is any value changing to 127, any row swapping images, or any image URL becoming unreachable.

1. Duplicate the export and retain the original file unchanged.
2. In the duplicate, locate the exact identity field used for product matching, normally the SKU field in the WooCommerce schema, and the product image field used by the importer.
3. Set the two fixture SKU cells to text values 00127 and 1270. If your spreadsheet offers a cell format, choose Text before entering the values; do not rely only on visually adding an apostrophe.
4. Save the duplicate, close it, reopen it, and inspect the displayed values. Export or save it in the CSV format required by your workflow, then reopen that CSV as text-aware data and inspect the same fields.

Branch on the evidence

If 00127 is still exactly 00127 after reopening the CSV, continue with the importer test. Use the importer’s own schema and mapping, inspect the exported sample rows, and review the matching or update selection before importing the fixture.

If it appears as 127, stop before importing. Reformat the identity column as text, re-enter the zero-prefixed values, and repeat the save-and-reopen test. If the value survives but the image is wrong, the issue is no longer numeric conversion: compare the row’s SKU, image URL, product identifier, and mapping selection, then test only the corrected fixture. If the URL cannot be reached by the importer, correct or host the image reference before testing identity matching.

Scale only after the test

Once the fixture passes, compare the production export with the edited CSV before a larger import. Check that product identity fields and original image references were preserved, and review the importer’s update matching before proceeding. Keep the original export so you can identify whether a later discrepancy came from spreadsheet conversion, mapping, or image retrieval.

Scope of the documentation

The official references below support tool behavior and feature boundaries. The test fixture, branching decisions and acceptance criteria are Itemlume editorial recommendations; citation does not imply endorsement. Illustrative sizes, names and timings are not your production specifications.