What does a provisional patent application actually do?

It secures a filing date and 12 months of 'patent pending' status for the invention it describes, nothing more. A provisional application under 35 U.S.C. § 111(b) is never examined and never becomes a patent; a nonprovisional application claiming its priority must be filed within 12 months, or the date is lost.

A provisional application is a placeholder with real force and real limits. Filed under 35 U.S.C. § 111(b), it establishes a priority date for whatever it adequately describes, allows the invention to be marked patent pending, and costs less because it requires no claims and is never examined. The 12-month clock is absolute: a nonprovisional application claiming its benefit must be filed within a year, or the priority date evaporates and the provisional expires. Priority matters because the United States awards patents to the first inventor to file (35 U.S.C. § 102), and an inventor's own public disclosure starts a one-year grace period for U.S. filing while destroying most foreign patent rights immediately. The trap is thin drafting: a provisional protects only what it describes in the detail the law requires (35 U.S.C. § 112), so a sketchy summary may secure nothing when the real application is later compared against it. Filed well, it buys a year to test the market before committing to full prosecution costs.

Authority: 35 U.S.C. § 111(b)