The international tax system incentivizes unsustainable business practices because it ignores the private profits created by offloading social and environmental costs to the public. This paper proposes a corrective in the form a blueprint for reforming the way multinational business is taxed. The blueprint calls for applying living wage and life cycle analyses to the rules for establishing market prices for tax purposes (namely, transfer pricing and permanent establishment income attribution rules). A relatively complex but arguably more accurate method and a complementary but relatively simpler proxy method are proposed. The blueprint addresses the implications of each method in the context of the legal parameters for cross-border tax cooperation via treaty-based and domestic coordinating rules and processes. The paper concludes that the blueprint provides a viable a starting point to make the global tax system support sustainable business practices without running afoul of international standards and without necessarily driving down foreign investment.