California Code, Business and Professions Code - BPC § 14415

The filing of articles of incorporation pursuant to Section 200 of the Corporations Code, in the case of a domestic corporation, or the obtaining of a certificate of qualification pursuant to Sections 2105 and 2106 of the Corporations Code, in the case of a foreign corporation, shall establish a rebuttable presumption that the corporation has the exclusive right to use as a trade name, in the state the corporate name set forth in the articles or certificate, as well as any confusingly similar trade name, if the corporation is the first to have filed the articles or obtained the certificate containing the corporate name, and is actually engaged in a trade or business utilizing that corporate name or a confusingly similar name.

If a foreign corporation continues to have authority to transact intrastate business pursuant to Section 2102 of the Corporations Code, the foreign corporation shall be considered to have obtained its certificate of qualification pursuant to law for the purposes of this section on the date it first qualified to transact intrastate business in this state.

The rebuttable presumption created by this section affects the burden of producing evidence.