The business license requirement is a local government issue. You'll need to check with the appropriate city, town, village, or county office. I believe an MT working from home for a national company is not really the "business owner." The national company is the business owner, and the MT is either an employee, a statutory employee, or a subcontractor. Still, it is advisable to contact local government regarding their requirements (if any) with respect to working out of the home.

I'm not entirely convinced that an IC works for a national company. To me, an IC is a business owner who determines his/her own rates, does his/her own billing and collections, solicits his/her own clients, determines when or when not to accept a particular client, etc.

If you do decide be an independent contractor and set up your own business, a tax consultant or accountant is advisable. There are issues you need to be aware of such as quarterly tax payments based on estimated earnings, yearly ad valorem taxes on your office furniture and equipment (if assessed locally), records of earnings/expenses that need to be maintained, etc. An accountant can help you navigate these tricky waters.

Another thought about starting your own business:
Have enough money in the bank to cover all your personal and business expenses for at least 6 months (a year would be better). It takes some time to build a business and, even if you have years of experience under your belt, there will not be clients lining up at your door the minute you get a license and announce you are open for business. There will likely be lean times with little $$ coming in. If you don't have the financial support of working spouse (SO) or another source of income, you'll need to have the funds to see you through until the business is established and profitable.