An investor questionnaire is a document a startup raising money from investors typically uses to help satisfy its burden of proving its investors are accredited investors. This is important to use because the startup has the burden of proof if challenged. If the startup sells unregistered securities to an unqualified investor, and thus can't perfect one of the transactional exemptions, then each purchaser (not just the unqualified investor) has the right to rescind its investment and have the purchase price returned.
