How to Open CSV Files Without Losing Long IDs (Google Sheets or Excel)

When you open a downloaded CSV directly in Excel, long codes (e.g., 14-digit school codes) can display as 1.23E+14 and appear altered after saving. This guide shows how to safely open and edit CSV files in Google Sheets or Excel without losing or changing long ID values.

Why: CSVs don’t store formatting. When you double-click a CSV, Excel auto-detects columns as Number (General) and may switch long values to scientific notation or “normalize” them when saved.

1) Easiest: Open in Google Sheets

Upload/import the CSV into Google Sheets (don’t open it with Excel), then work there and export the finalized CSV to Excel if needed.

2) Excel (Legacy Text Import Wizard)

Why: Lets you set columns to Text during import.

• Enable once (Excel 365/2016+):
  File → Options → Data → Show legacy data import wizards → check From Text (Legacy) → OK.
• Import:
  Data → Get Data → Legacy Wizards → From Text (Legacy) → pick CSV →
  Step 1: Delimited → Next →
  Step 2: Comma → Next →
  Step 3: Click each long-number column → Text → Finish → choose destination.

3) Excel (Power Query)

• Step 1: Data → Get Data → From Text/CSV → select CSV →
• Step 2: Set Delimiter as needed → set Data Type Detection = Do not detect data types →
• Step 3: Click Transform Data → set long-number columns to Text → Close & Load.

Quick tips:

• Don’t double-click CSVs with long IDs—always import.
• Set Student ID / Order ID / Phone / ZIP columns to Text.
• Once digits are altered in Excel, they can’t be recovered from that file—reimport from the original CSV.