A corporation, limited liability company, limited partnership or limited liability partnership which regularly conducts business or renders a professional service in Texas under a name other than its legal name (as stated in its certificate of formation or amendments thereto) must file an assumed name certificate with the Texas Secretary of State. In addition, an assumed name certificate must be filed with the county clerk in the county in which the registered office is located and the county in which the principal office is located if these are not the same county.