How Excel silently destroys your GTINs (and how to get them back)

Updated July 2026

In the catalogs we audit, spreadsheet damage is the single most common source of invalid GTINs — more common than typos, more common than genuine data-entry mistakes.

The two failure modes

1. Leading zeros stripped

Excel treats a GTIN as a number, and numbers do not have leading zeros. 036000291452 silently becomes 36000291452 — eleven digits, which is not a valid GTIN length at all. The check digit is still technically correct, but the identifier is wrong.

2. Scientific notation

Any number longer than 11 digits may be displayed — and, critically, exported — as 8.85911E+11. Unlike the leading-zero problem, this is unrecoverable from the file alone. The original digits are gone.

Prevention

• Format the GTIN column as Text before you paste or import anything into it.
• When opening a CSV, use Data → From Text/CSV and set the GTIN column type to Text in the import dialog. Double-clicking the file skips this step and the damage is done before you see the sheet.
• Export as CSV with the column still formatted as Text. Check the raw file in a text editor — what you see there is what your trading partners receive.
• Google Sheets has the same behaviour. Format → Number → Plain text, before pasting.

Recovery

For stripped leading zeros, zero-pad back to a valid length (8, 12, 13, or 14 digits) and verify the check digit — if it validates, you have almost certainly recovered the correct identifier. For scientific-notation damage, you must go back to the source system; the spreadsheet no longer contains the answer.