How to Open a CSV in Excel Correctly (columns, zeros and dates intact)

Double-clicking a CSV lets Excel guess everything. Usually fine, sometimes it eats your zeros. Three more clicks avoid it.

Steps

1. Open Excel with a blank workbook.
2. Data › From Text/CSV › pick the file.
3. Preview: check Delimiter (Comma; change to Semicolon or Tab if it all sits in one column).
4. Data Type Detection › Do not detect data types if you have codes with leading zeros.
5. Load.

Everything landed in one column

The separator is not a comma. In step 3 try Semicolon, then Tab. If you already opened it: select column A › Data › Text to Columns › Delimited › tick the right separator.

Strange characters (é, ’)

Step 3: File Origin › 65001: Unicode (UTF-8).

Just a quick look

Double-click is fine when you only need to read. Don’t save over the original from Excel — that is when damage becomes permanent.

Keep working with it

File › Save As › Excel Workbook (.xlsx). A CSV cannot hold formatting, formulas or extra sheets.

Check it worked

Open the CSV in Notepad. A code that starts with 0 there must start with 0 in Excel. A date must be the same day and month.

Make CSVs always open this way

Right-click the CSV › Open with › Choose another app › Notepad › tick Always. Then CSVs open as text and you import them into Excel on purpose.