At present it is mandatory to fill in country field on Customer & Supplier profile screen.  Our company is located in the UK and 99% of work is within UK thus rendering this field unnecessary in our circumstances.  However the country (United Kingdom) will always be shown on the invoice (unless removed manually on each invoice which is time consuming)  If the field were optional or the selection could be "none" and left blank this would be helpful to small business who only operate in the UK.