||A trade name is any name used by a business that does not include the full legal name of all the owners of the business. For a limited partnership or a corporation, it is a name that differs in any respect from the name registered with Washington's Secretary of State.
While trade name registration provides a record of all owners of a business, it does not prohibit others from using the same name. However, if you conduct business and use a name other than your legal name, Washington law requires you to register it as a trade name.
For more information regarding trade names, please refer to Business Licensing Service's website.