The rapid expansion of global e-commerce has outpaced regulatory systems governing cross-border digital trade, customs processes, data flows, taxation, consumer protection, and digital payments. Policies enacted by national governments and regional blocs significantly shape the feasibility, cost, and competitiveness of cross-border transactions. This paper examines policy dimensions influencing cross-border e-commerce, including data privacy laws, tariff and customs regulation, digital service taxes, cybersecurity requirements, logistics protocols, and consumer rights frameworks. Using hypothetical datasets and theoretical comparative analysis, findings reveal that harmonized regulatory environments facilitate higher cross-border adoption, while fragmented policies increase cost, compliance burden, and market entry barriers. A policy-coordination framework is proposed for enhancing seamless digital trade.