Most travel agencies charge a service fee, usually a minimum of $25.00 per person plus GST for most bookings made.y service fee will be $25.00 plus GST per person for domestic and trans-border travel, with a maximum of $50.00 plus GST per family. For some international bookings my service fee will be $35.00 plus GST, with a maximum of $70.00 plus GST per family.