Common Law Trademark

General Sources of Business Names

Search general business directories to find out what names are in use.

California Businesses

California Business Search - CA corporations (including nonprofits), limited partnerships (LP) and limited liability companies (LLC). Also try the Name Availability searches.

Fictitious Business Name (FBN) Search

San Francisco Fictitious Business Name Search.

Print Directories of Local Businesses

[See Local Company Research Resources for a more complete list of local sources]

General Sources of Brand & Product Names

  • Brands & Their Companies - U.S. listings of trade names and products. Current
  • The Advertising Red Books (formerly "Standard Directory of Advertisers") - brands and advertisers are indexed by industry and location.
  • ThomasNet (manufacturers and their brands)

Sources for Specific Goods & Services

The Business, Science & Technology Center has many print trade directories for a wide range of industries. 

  • National Register of Apparel Manufacturers.
  • RN & WPL Encyclopedia - best source for identifying clothing labels and manufacturers. Up to 2009

Additional Suggestions

  • Search the Internet for your prospective trademark. Use a search engine like Google for a broad search or try an index such as Yahoo to concentrate on a business or product category.
  • Scan trade magazines for business and product names. Business Publication Advertising Source from Standard Rate & Data Service is an excellent source of industry publications. Check the Library’s catalog to see if SFPL has any of the industry titles.
  • Consult local and regional yellow pages.
  • For special types of businesses, consult a library center that specializes in a related subject. For instance, ask staff at the Art, Music, and Recreation Center about searching for band (music) names.
  • There are companies that perform trademark searches for a fee. They can be located in the phone book under “trademark consultants,” or found online in library databases such as Reference USA.
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