Keep leading zeros in CSV SKUs and barcodes
A SKU is an identifier, not a number. The strings 00124 and 124 can identify different products. Once a spreadsheet saves the shortened version, a CSV preparation tool cannot know which digits were lost.
By FeedNeat · Reviewed October 26, 2026
Check the original file first
Keep an untouched supplier file. Inspect a known SKU in a plain-text viewer before opening a working copy in a spreadsheet. If the source already contains 124, do not guess that it should be 00124. Ask the supplier or compare with an authoritative product record.
Import identifiers as text
Use your spreadsheet application's CSV import controls to assign text types to SKU and barcode columns. Changing a number's display format after import is not proof that the underlying identifier is intact. Save a copy and inspect the resulting text again.
Verify what will be exported
FeedNeat parses CSV values as strings. Map the supplier identifier to SKU or Barcode, then compare the export preview with the original. For example, 00124 should remain 00124. Trimming outer whitespace is an optional preparation rule and appears in the change review.
Avoid a second accidental conversion
After export, inspect the CSV as text or import it with explicit text-column types. Double-clicking it in a spreadsheet can trigger another round of automatic number conversion. A correct exported file can look incorrect in a spreadsheet that has reinterpreted its contents.
Worked example
Supplier value: 00124 Expected exported SKU: 00124 Already damaged source: 124 → verify with supplier; do not invent zeros.
Related guidance
- Complete pre-import checklist
- Fix ambiguous prices in a supplier CSV
- Understand repeated handles in a Shopify CSV
For the destination format and field dependencies, consult the official Shopify CSV reference. FeedNeat is independent software and supports a limited subset.