A Section 25102(f) notice filing refers to a California state filing that startups typically rely on when selling shares to founders based in California. Section 25102(f) of the California Corporations Code is a California state exemption from the requirement to register a securities offering. For startups issuing shares to founders, they typically rely on Section 4(a)(2) of the Securities Act. However, Section 4(a)(2) doesn't preempt state securities laws, and so the California exemption under Section 25102(f) is usually relied on for shares issued to founders based in California.
To meet this exemption, a startup must file the 25102(f) notice, which is called a "Limited Offering Exemption Notice", within 15 days of after the first sale of a security in the offering in California. The notice can be filed electronically via the California Department of Corporations website.