Permanent establishment: criteria for fixed place, dependent agent, and exclusions determining taxable presence under a tax treaty. Permanent establishment is a fixed place of business through which an enterprise's business is wholly or partly carried on, including management, branches, offices, factories, installations for resource extraction, warehouses, sales outlets and construction sites subject to duration rules. Exclusions cover preparatory or auxiliary activities, storage or display of goods, stock for processing, purchasing, information gathering and occasional exhibitions. A dependent agent with authority to conclude contracts, or habitually maintaining stock or securing orders, creates a permanent establishment; an independent agent acting in the ordinary course of business does not unless devoted almost wholly to the enterprise. Control alone between related companies does not suffice to create a permanent establishment.