I have a .co.uk domain name and want to use it with word press. Why is it not allowing me to use it when I put the domain name in, does it only allow .com domain names?
you can first register with a normal sub-domain ... Later go to the domain name on your backend and add the domain name as you wish... Thing to be noted Mapping a domain you already own costs $12.00 per domain, per blog, per year. More info here: http://en.support.wordpress.com/domain-mapping/