Promoting Startup Innovation Act - Amends federal patent law to modify the definition of "micro entity" (certain small entities eligible for reduced patent fees) to require applicants to certify that they: (1) have not been named as an inventor on more than seven (currently, four) previously filed patent applications, subject to applicable exceptions for applications filed in another country, provisional applications, or international applications under the Patent Cooperation Treaty; and (2) did not have gross income exceeding five times (currently, three times) the median household income in the preceding calendar year and have not transferred ownership interest in the application to an entity with gross income exceeding such limit.

Requires the Director of the U.S. Patent and Trademark Office (USPTO) to approve or deny such applications within 45 days after the application is submitted.

Applies such amended requirements to applications submitted on or after the enactment of this Act.