How to Check LLC Name Availability in Washington (Step-by-Step)

Quick Answer: Search the Washington Secretary of State (SOS) business name database through the WA Corporations & Charities Filing System (CCFS) at ccfs.sos.wa.gov. Your name must include an approved LLC designator, be distinguishable from existing names on record, and avoid restricted words. Then check your domain separately — or run both checks at once at BizNameChecker.com.

Washington had approximately 790,000 small businesses as of 2023, according to the SBA Office of Advocacy. Most of those founders ran into the same wall: the state name search and the domain search live on two separate platforms, in two separate browser tabs, with zero coordination between them. This guide closes that gap. Follow these steps in order, and you will know your name is clear — on paper and online — before you file a single document.

Step 1: Confirm Your Name Meets Washington's Naming Rules

Washington LLC naming rules disqualify non-compliant names before they ever reach a search.

Under Revised Code of Washington (RCW) 25.15.006 and Washington Secretary of State (SOS) filing rules, every LLC name must include one of these designators: "LLC," "L.L.C.," "Limited Liability Company," or another approved abbreviation. The name must also be distinguishable upon the records of the Washington Secretary of State (SOS). This means it cannot be identical to or deceptively similar to an existing entity name already on file.

Restricted words add another layer. Terms like "bank," "insurance," "attorney," and "engineer" require additional licensing or agency approval before the Washington Secretary of State (SOS) will accept the name. Check the restricted words list on the SOS website before you commit to a name that the state will reject at filing.

Key Takeaways:

• Every Washington LLC name requires an approved designator such as "LLC" or "Limited Liability Company"
• Names containing restricted professional terms require pre-approval from the relevant licensing agency
• According to RCW 25.15.006, your name must be distinguishable upon the records of the Washington Secretary of State. This requirement prevents identical or deceptively similar registrations

Step 2: Search the WA Corporations & Charities Filing System (CCFS)

The WA Corporations & Charities Filing System (CCFS) at ccfs.sos.wa.gov is the official portal for searching Washington business names.

Go to ccfs.sos.wa.gov, select the business name search function, and enter your proposed name. The system searches active entities on file with the Washington Secretary of State (SOS) and returns matching or similar results. Run multiple variations. Search your exact name, then search without the designator, then search common misspellings. A name that looks unique to you may be flagged as not distinguishable from an existing registration.

One critical limitation: the WA Corporations & Charities Filing System (CCFS) does not check domain availability, trade names registered with the Washington Department of Revenue (DOR), or entity names in any other state. Those are separate searches. The state portal answers one question only: is this name currently taken in Washington's LLC registry?

Key Takeaways:

• The WA Corporations & Charities Filing System (CCFS) at ccfs.sos.wa.gov is the only official source for Washington LLC name availability
• The CCFS search does not cover domains, trade names, or out-of-state registrations
• Search multiple variations of your proposed name to catch all potential conflicts

Step 3: Check Washington Trade Name (DBA) Registration Separately

Washington runs a dual-track system that confuses most first-time founders. LLC names and trade names are not the same registration.

If your LLC will operate under a name different from its legal LLC name, that operating name is a trade name, commonly called a DBA. Trade names are not filed with the Washington Secretary of State (SOS). They are registered with the Washington Department of Revenue (DOR) at dor.wa.gov. The filing fee is $5, and registrations remain active indefinitely according to the Washington Department of Revenue (DOR).

This split creates a real problem. The top search result for "Washington business name registration" often surfaces dor.wa.gov, which covers trade names, not LLC formation. Founders