Issue with selecting columns via macros

Instead of using Select/Selection try explicitly referring to the column(s).

Which column(s) do you want to format?

 'Copy from CSV to Quote and delete first row
    Sheets("CSV").CurrentRegion Sheets("Quote").Range("B12")

    With Sheets("Quote")
        .Rows(12).Delete
        .Columns(3).NumberFormat = "@"
    End With