Public policy initiatives demand transparency of information privacy practices (TIPP) since the 1970s, at least, when a first version of the fair information practice principles (FIPP) was published. Decades later, information system (IS) providers are still struggling to meet this demand. Apparently, there is a tension between socially desirable guardrails for privacy practices (e.g., allowing for anonymity) and economic value creation (e.g., exploiting personalization surplus). To inform IS designs that can change such avaricious states to the benefit of consumers, we present a theoretical foundation (TIPP theory) explaining and prescribing what needs to be built to establish TIPP in the real world. On the one hand, TIPP theory explains why IS providers, who have privacy practices to hide, should not go beyond IS designs that meet legal demands. More importantly, TIPP theory explains and prescribes what IS providers need to build to actually establish TIPP and be able to differentiate from competitors by doing so. TIPP theory will be useful for all involved parties: IS providers are enabled to avoid privacy notice fallacies, public policy makers can give more details in their related guidance and laws published, and consumers can, ultimately, interact with IS that actually establish TIPP.