What if I’m opening a CSV (I think the wizard might handle that if you are really careful with it) or pasting a large dataset? All I know is that I’ve struggled with this in the past, and not because I don’t know my way around Excel.
If you need the numbers as numbers (for example, to do math with them) then it's not a solution. But if the numbers are just identifiers (like Client IDs, phone numbers, etc) then telling Excel that they are text will give you a much better experience. There are lots of ways to do this in Excel, e.g. in "Format Cells", or by using the =TEXT() formula, etc) but those settings will be lost if you save it to CSV
My preference is to insert an apostrophe before the number. It's an invisible character in Excel, and is preserved even if you save as CSV.
If you're importing from a CSV, the last step in the Text to Columns wizard lets you identify columns as values or text.
