Depending on whether your OS uses a , or a . for decimal numbers changes how excel will parse a CSV file. Americans use a . for decimal numbers, so it will parse it as a CSV. Other countries use a , for decimal numbers, so it will parse it as a SSV (semi-colon separated) and everything will be in a single column.
To make matters worse, randomly, employees will have their OS using US or GB locales so that if you distribute a CSV, it will work for some employees, but not for others.
No. Excel changes the SEPERATOR when parsing depending on the locale settings. This means a CSV generated or saved with a decimal of . will not be able to be opened by one with a , and vice-versa. This is an Excel issue, as it doesn’t even try to determine or ask which separator to use. Hence why the comment above said you need to use the import wizard and not double click.
The syntax that MS Office uses to read/write a CSV is defined by the Regional Settings of your PC.
Open control-panel for regional settings, select "Advanced settings" button on the bottom
control.exe intl.cpl
If you don't know any of these problems, then all the people and systems you work with have a "." as decimal and "," as separator, and you are spared from the hell of MS Office being unable to overrule these OS-settings when treating a CSV
Honestly as this always was an obvious issue I usually just used ; and never got a complain. Obviously both . And , are used way to often not only for numbers. I am surprised this is problem enough (in 2025) that people emotionally discuss it.
> Honestly as this always was an obvious issue I usually just used ; and never got a complain.
Thing is, it is not about what you used, you are not able to control this from happening when your CSV should work for people in other countries. Whatever configuration you used which never got a complain, if your recipients also used Excel to work with those documents, they probably have the same regional setting on Windows for list/thousands/decimal separator.
If you use ";" as separator, i.e. Excel in UK, US, Japan, China, Korea will not be able to correctly open your CSV.
But even better: If you created this CSV on a France or Sweden regional setting, the thousands separator will be a whitespace ("1 000" instead "1,000" or "1.000"), so Excel in e.g. Italy will not detect those properly.
> I am surprised this is problem enough (in 2025) that people emotionally discuss it.
It is a (intentional) weakness of MS Office for those who work in an international environment, because Excel links itself to .csv files to hinder the experience, as it is neither able to properly detect them nor guide their users through a process to properly handle them.
CSV already solved this problem with quotes. Maybe not the most convenient solution for some users but that's no excuse for the Excel behavior of making up a different format depending on the locale.
Excel really doesn't care what users think. I mean, in biology, we've already had to change the names of genes to accommodate Excel's auto-date conversion routines. So, why would it care to have globally consistent CSV formats?
To make matters worse, randomly, employees will have their OS using US or GB locales so that if you distribute a CSV, it will work for some employees, but not for others.