Most or perhaps all states' financial codes prohibit legal business entities such as corporations or LLCs from acting as trustee unless they have applied for and been granted trust powers under state law, which requires meeting certain regulatory requirements including solvency and experience. I am not sure, but suspect that even an individual (who generally can act as trustee under state law), e.g. a TPA that who was a sole proprietor, might also violate state law if he or she carried on a trust business.