Hired an employee who lives in South Carolina but Works in North Carolina. But the company doesn't have a physical location in North Carolina.

We recently hired an employee who lived in South Carolina but going to work as a "remote sales" in North Carolina. What she does is basically visit clients in North Carolina so she'll always be on the road.

 

Our company is registered in other states(IL and GA) but not in SC or NC. And we don't have a physical location in either SC or NC. How do we withhold the employee's state income taxes? Do we need to register our company in North Carolina?

 

Thanks.