I presume you are referring to a csv file. I also presume that you can create the csv file from whatever is the source, something other than TB. The safest way I have found is this: - add at least one email address manually to the TB addressbook - then, highlight the addressbook, click the three dots to the right, download a csv file. - this is now your master template. open it in a spreadsheet program, alongside an opened csv file from elsewhere. rearrange the columns to match the layout (and first line) that you see in the TB's csv file. - save as csv - you now have a csv file that is perfectly aligned for importing to TB.