‘Due diligence’ is an M&A term for any investigation that the buyer does to know what he/she is buying (like wine tasting, but for companies). Startup founders typically encounter ‘due diligence’ as a time-consuming activity when they want to sell (part of) their business. Typically a due diligence is done at least on company legal structure, tax liabilities, financial numbers, the business plan, market assumptions, and for large older companies also on pension obligations that are not accounted for. More recently, many buyers insist on a software due diligence: a review of the software of the company to be bought. In this article we help you as a founder manage the software due diligence phase.