Permanent establishment expanded agency rules broaden taxable presence where intermediaries habitually conclude contracts for foreign enterprises. Revisions to the OECD Model treat intermediaries whose activities are intended to result in the regular conclusion of contracts for a foreign enterprise as creating a taxable presence unless the intermediary is an independent business; Article 5(5) and 5(6) amendments and an anti-fragmentation rule narrow preparatory or auxiliary exceptions and aggregate cohesive activities of closely related entities, with implementation through the multilateral instrument and domestic alignment to ensure attribution and effectiveness of PE rules.