Most business don't deal with 50 states.
Most businesses of any size send sales people to travel in many of the 50 states as well as all over the world. So they would be subject to audit for their Holiday Inn room bill in Wenatchee, Washington as well as their lobster dinner in Kennebunkport, ME.
That brings up another point, business expenses spent in a foreign country (Like a german trade show) are currently deductible from a business' profits. I guess with no income taxes it really doesn't matter about the foreign expenses, there will be no tax forms to record these items on anyway.
This no income tax stuff is hard to grasp the way it will all actually work.