A business can register an unlimited number of trade names. A trade name will remain registered indefinitely until the owner requests that it be canceled.This page includes forms, fees, and instructions for all domestic business entities, foreign and domestic Registered Agents, and Washington Trademarks. Your business's name must end with the words "Limited Liability Company" or "Limited Liability Co.," or the abbreviation "LLC" or "LLC". Bizee offers a fast, simple and convenient tool to look up your proposed business name. An LLC beginning business in Washington State must file formation documents with the Washington Secretary of State. Learn what you need to know about naming an LLC in DC with Bizee's helpful resources. Pick your perfect business name today! In order to establish a trade name in Washington, it's necessary to submit a Business License Application to the Department of Revenue. You must list a name for your Washington LLC.