Permanent establishment definition clarifies fixed place and agent-based attribution leading to taxation exposure under treaty. Permanent establishment is a fixed place of business through which an enterprise's business is wholly or partly carried on, including management offices, branches, factories, workshops, certain warehouses, agricultural and extraction sites; building sites and construction or installation projects count as permanent establishments only when they exceed the Article's temporal threshold. Excluded are facilities used solely for storage, display, delivery, stock maintenance for storage or processing, purchasing or information collection, and preparatory or auxiliary activities. A person (other than an independent agent) habitually authorized to conclude contracts in a Contracting State creates a permanent establishment for the enterprise unless the activities fall within those exclusions.