Laws and regulations hindering data flows across borders are trade-restrictive, and some of these measures can violate WTO and PTAs' obligations. The chapter starts by exploring the multi-layered policy framework governing data flows and cross-border data flows identifying various policy goals typically associated with data restrictions. This includes exploring the various elements required within the WTO framework to address the policy ramifications of data restrictive measures, focusing on General Agreement on Trade in Services (GATS). The chapter then explains the trade-related aspects of data flow regulation by focusing on two interconnected topics: (i) the special nature of digital trade and trade in data that makes it harder to apply existing GATS provisions to digital services; and (ii) those aspects of data flows that are trade-related and, thus, should be addressed in a trade law framework. Finally, the chapter proposes a novel WTO framework on data flows by identifying the foundational principles for data regulation and the legal provisions necessary to enable security, predictability and certainty in data flows.