Phone numbers turn into dates or lose their leading zero in Sheets/Excel
Why spreadsheets change phone numbers on import or export, and how to keep them intact for your CRM.
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Format phone numbers →Why this happens
- Automatic formatting reads numbers like 06-12 or 1/2 as dates.
- Numbers are stored as numbers, so the leading 0 is dropped.
- Long numbers are shown in scientific notation (3.16E+10).
How to fix it
- Format the phone column as plain text before pasting or importing.
- Use the international format with country code, e.g. +31612345678.
- Check a few rows after export — dates and E+ numbers can't be recovered automatically.
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