CSV Import Checklist: Keep IDs, Dates and Columns Intact

Start with a small, safe test

Use a copy of your file and import a handful of representative rows first. Include an ID beginning with zero, a date, a name with an accent and text containing a comma. Those rows expose common interpretation errors before they spread through a larger import. Download our fictional practice CSV to try the checks below; it contains no real customer data.

Import deliberately

1. Open the CSV through your spreadsheet’s import workflow rather than relying on a double-click. Inspect the preview.
2. Choose the character encoding that matches the file. If accents look wrong, stop and change the encoding instead of editing each name.
3. Choose the correct field separator and text delimiter. A row should split into the intended columns.
4. Set identifier columns to Text when their characters must be preserved. Treat a product code or postal code as an identifier, not a quantity.
5. Choose date interpretation deliberately, particularly when day/month order could be ambiguous.
6. Check row counts and several values against the original text before accepting the import.

Why leading zeros disappear

A spreadsheet may interpret 00123 as the number 123. In LibreOffice’s Text Import dialog, selecting the Text column type preserves a leading-zero identifier. Its official documentation also explains character sets, separators and date column types; the source is linked below.

Changing display formatting after a value has already been converted does not prove that the original identifier was preserved. Inspect the CSV in a text editor and compare the imported value. If zeros are missing in the raw file, the import cannot infer how many there should have been.

CSV is a data exchange format

Keep the original workbook if you need sheets, styling or formulas. A CSV is a plain-text table; it is not a complete replacement for a workbook. Before converting XLSX to CSV, decide which table you intend to export and verify the output. After converting CSV to XLSX, recheck the fields instead of assuming the new extension corrected their interpretation.

A useful final check

1. Count columns in the header and inspect several rows.
2. Compare identifiers character for character.
3. Inspect accented text and quoted commas.
4. Check dates against an unambiguous reference.
5. Compare the number of data rows, excluding the header.
6. Keep the untouched input alongside the validated result.

Frequently asked questions

Does quoting a value always force every spreadsheet to treat it as text?

No. Import behavior varies. Explicitly select the column type in the receiving application and verify the result.

Can a converter restore zeros that were already lost?

No. You need a trusted original or an explicit rule defining the correct identifier length. Do not guess from neighboring rows.

Sources and further reading

• LibreOffice Text Import documentation