The most important aspect of growing your business nationwide is trademarking your name. If you are currently operating a successful brand locally as opposed to nationally, other businesses may be able to establish themselves in a different area of the country using your brand name.
Registering a domain name in Go Daddy does not prevent other businesses from using your brand name. Under the Fair Trading Act of 1986, the business's reputation in the market place determines the extent to which the business will be able to enforce their rights. To avoid costly legal battles the best protection is by registering your brand as a trademark under the Trade Marks Act of 2002.
If you do not have a Trademark attorney, we would be happy to refer you to ours.