Permanent establishment rules define fixed place and agent activities that create a taxable nexus, with duration thresholds for projects and services. Article 5 defines permanent establishment as a fixed place of business and lists typical forms (management, branch, office, factory, workshop, sales outlet, warehouse, agricultural and extraction sites). It treats construction sites and service provision through personnel as creating a permanent establishment when activity exceeds specified duration thresholds. Exclusions apply for solely preparatory or auxiliary activities and for independent agents acting in the ordinary course of business; dependent agents who habitually conclude contracts, maintain delivery stock, or secure orders create a permanent establishment. Insurance activities via non independent persons also create a permanent establishment, while corporate control alone does not.