I am trying to register an online business, am using a virtual address in another.

In order to conduct business in the state of Virginia and in any given town, you need to register with the State Corporation Commission and do a lot of other steps for incorporation. These steps are crucial as you could be facing serious trouble should you operate a business without the proper licensing and registration. It is highly advisable that you seek a business attorney who handles incorporation. You may find one by using the search function at the top of .

Either an S or LLC taxed as a disregarded entity make sense, unless you need VC funding in which case you might want to consider a C corp. There are many factors consider in chosing: taxes, investors, reporting obligations..etc. It is hard to advise you in a vacuum and you should seek legal guidance. As for where to register? If you are operating from Virginia you should look at forming an entity in VA.