Product codes and reference numbers are identifiers, not amounts to add together. Treat them as text before import. If a code appears with E+ or changed final digits, inspect the source before saving over it.
Display change or changed data?
Microsoft states that Excel has 15 significant digits of numeric precision and recommends text for codes of 16 digits or more. Formatting an already altered value does not recover its missing digits.
| Symptom | Our suggested check |
|---|---|
| Cell displays E+ | Select it and compare its value with the original CSV |
| Final digits become zeros | Stop using that copy and import the original again |
| Leading zeros disappear | Import the column as text |
| The source already has wrong digits | Request a fresh export from the source system |
Scientific notation alone does not prove data loss. Compare the complete value, especially the final digits.
Choose a type during Excel import
Use Data → From Text/CSV and set the identifier column to Text before loading, following Microsoft's import guidance. Menu names vary by version. Keep quantities numeric when you need calculations.
Our recommendation is to work in a new workbook and preserve the received CSV until checks finish. Once an altered value has been saved back into the source, another format conversion cannot infer the old code.
Convert a copy with FileMyLove
Open Convert document, select CSV and export XLSX. Our reader stores uninterrupted whole-number strings of 12 or more digits as text, as well as values with leading zeros. It does not validate whether an identifier exists.
Try fictional values such as 001234 and 123456789012345678 before processing a real dataset. The converter preserves available source text; it does not restore missing digits.
Verify the handoff
Compare codes near the start, middle and end with the original. Check row and column counts separately from number appearance. If exporting back to CSV, verify the recipient's import settings too: XLSX does not control how another program interprets a CSV.
For garbled Thai or incorrect column separation, see CSV encoding and delimiters, a different issue from long-number precision.
