Yes you can as when data is imported into your CRM account from a spreadsheet – if the Custom Fields do not already exist inside your account then they are created during the import and any information contained is added.
Please note: that the custom field will be set up as a text format field.
If you later wish to change the format of this text field to another format such as a drop down or checklist you must contact our Support Helpdesk as it will require our Technical team to change this for you, if you try and change the format of a custom field you will lose any data that has already been captured against your contacts.
If the Custom Field on the spreadsheet does not contain a tag association then we ‘presume’ the custom field should be created with no associated tags and therefore is applied to all contacts.
Please contact our Support Helpdesk to discuss your change requirements further.