A customer reference such as 00127 is not the number 127 wearing extra decoration. Those first two zeros may be part of an identifier. If you open a CSV and let a spreadsheet guess the column types, the result can look tidy while silently changing the data. LibreOffice CSV import gives you control over column types, before those distinctions disappear.
Prepare a LibreOffice CSV import without touching the original
Make a working copy of the CSV and keep the downloaded original unchanged. Give the copy a meaningful name, such as supplier-list-working.csv, rather than editing a file whose only other copy lives in an email attachment. If several people use the list, record its source and download date outside the data itself.
Before opening Calc, inspect a few lines in a plain-text editor. Look for the delimiter, any quoted fields, accented characters and columns containing identifiers. Use invented examples while learning: a reference like 00127, a phone-like string and a description containing a comma reveal several import mistakes immediately. Do not upload real customer records to an online conversion service just to see how they look.
The aim is to distinguish values you calculate with from strings you preserve. Quantities and prices often belong in numeric columns. Order codes, membership identifiers and telephone entries often belong in text columns, even if every character happens to be a digit.
Tell Calc which columns must remain text
Open the working CSV through File, Open, selecting Text CSV where necessary. In the import dialog, choose the actual separator and inspect the preview. If each row appears in one giant column, the separator is probably wrong. If a description breaks into several columns, check the quote or string-delimiter setting rather than manually moving hundreds of cells.
Click the preview heading for an identifier column and set its column type to Text. Repeat this for each column that must preserve its original strings. The official Text Import help describes the column-type selector and the other controls. Merely turning off Detect special numbers is not equivalent to forcing text: ordinary decimal-looking values can still be converted.
Check the character set against the preview as well. A supplier name containing Bangla or another non-Latin script should remain readable. Do not assume that a visually plausible English header means every character in the rest of the file decoded correctly. Inspect examples from several rows, including a name you can independently recognise.
Keep ambiguous dates and untrusted formulas under control
A field such as 03/04 is ambiguous without knowing its intended format. If the column is an identifier, import it as text. If it is a date, confirm the source convention before choosing a date interpretation. Guessing based on the first few rows is especially risky when a list mixes exports from different regions.
For an unfamiliar CSV, leave Evaluate formulas disabled in the import options. LibreOffice documents that this setting controls whether expressions beginning with an equals sign are evaluated or imported as text. A contact list should not need to run formulas supplied by a stranger. If the file contains unexpected formula-like entries, investigate the source before handing it to colleagues.
Once imported, inspect a leading-zero example in the input line, not just the cell’s appearance. A custom numeric display can make a value look padded without restoring its original meaning as text. If conversion has already removed information, reopen the untouched CSV with corrected import settings rather than guessing how many zeros belonged there.
Validate the export, not only the worksheet
Save your editing master as an ODS spreadsheet so that the working file retains spreadsheet structure and formatting. Make a separate CSV export for the system that needs it. Check that you are exporting the intended sheet and that the destination accepts your chosen separator and character encoding. A CSV exchange file is not a replacement for a multi-sheet workbook.
Open the exported CSV in a plain-text editor and compare representative records against the original. Confirm that 00127 remains 00127, descriptions with commas remain one field, and names still display correctly. Then import the export into a fresh Calc window using explicit text types again. This second pass tests the handoff rather than trusting the appearance of the original worksheet.
If the next recipient’s software still strips zeros, agree on import instructions or an identifier format before sending the real list. For related spreadsheet habits, see our beginner spreadsheet skills and file-organisation guide. Keep the untouched source until the destination has accepted and validated the records.