A Washington single-member LLC operating agreement is used by the sole owner of a limited liability company to establish their rights and responsibilities with respect to the business. While not required by law in Washington, this document helps the owner to protect personal assets from the financial and legal liabilities of the company. In addition, internal procedures related to meetings, voting, dissolution, and succession can be determined in the document. Without an operating agreement in place, the company is subject to default state rules governing LLC operations. Because the document only has one signatory, it should be signed and dated in the presence of a notary public.