Tax Residency
& Cross-Border Structure

The Problem

Tax residency is the most consequential jurisdictional decision a mobile private client will make — and the one most frequently made by default rather than by design. Where you are tax resident determines which government claims primary jurisdiction over your worldwide income. That determination is governed by rules that vary significantly across jurisdictions and interact in ways that most single-jurisdiction advisors are not positioned to see.

The risk is not aggressive planning. The risk is inattention — allowing tax residency to be established or maintained in a jurisdiction you did not consciously choose, under terms you did not evaluate.

Treaty Architecture

Double tax treaties create the framework within which mobile clients manage multi-jurisdictional exposure. Treaty tie-breaker provisions, permanent establishment rules, and beneficial ownership standards all affect where income is ultimately taxed. We map these interactions before residency decisions are made, not after — because once tax residency is established, the treaty framework is already determining outcomes.

U.S. Person Considerations

U.S. persons face constraints that no other nationality imposes: worldwide taxation regardless of residency, FATCA reporting obligations that restrict banking access globally, and the interaction effects between foreign tax credits, treaty elections, and the IRC provisions that govern cross-border structures. Our analysis for U.S. clients integrates these requirements from the outset, because they constrain every other decision in the architecture.

Territorial vs. Worldwide: It Is Not That Simple

The distinction between "territorial" and "worldwide" tax systems is useful shorthand but frequently misleading. Panama's territorial system does not tax foreign-source income — but the definition of "foreign-source" is narrower than most clients assume. Portugal's IFICI regime offers favorable treatment — but the qualifying conditions and duration have changed. We evaluate the actual operating environment, not the marketing language.