Territorial extension of tax convention permits application to dependent territories with similar taxes, subject to agreed modifications and termination. Article 30 permits extension of a Model Tax Convention to territories for whose international relations a Contracting State is responsible when those territories impose taxes substantially similar in character; extensions may be full or modified and take effect from dates and on modifications and conditions agreed by the Contracting States, to be specified in notes exchanged through diplomatic channels or other constitutional procedures; absent agreement to the contrary, termination of the Convention by a Contracting State also terminates its application to any territory to which it had been extended.