Whichever data import template you use you will see a column heading called Categories as shown below in the screenshot:
This column called Categories is where you enter your tag group(s) just enter each tag name separated by a comma (,) and NO SPACE – i.e. customer,south-west,new-lead (these are then automatically imported as tags within your CRM account and are used to segment your contacts into different categories).
If you have any questions please contact our Support Helpdesk.