If you are registered as a corporation or limited liability company in another state or country and are doing business in Washington, you will need to fill out a “Foreign Profit Corporation – Certificate of Authority” or “Foreign LLC Registration” form with the Office of the Secretary of State.
LLC members may be any person or organization while S Corporation shareholders must be individual U.S. citizens or U.S. residents, estates or certain trusts (they cannot be other corporations or LLCs). Also, the number of shareholders is limited for an S Corporation while an LLC may have an unlimited number of members.
State law permits a local government to enter into interlocal agreements with other public agencies in the interest of cooperatively sharing resources for their mutual benefit. RCW 39.34.