(a) Article 13 shall apply to taxes.

(b) Whenever an issue arises under Article 13, to the extent it pertains to whether a tax constitutes an expropriation or whether a tax alleged to constitute an expropriation is discriminatory, the following provisions shall apply:

• (i) The Investor or the Contracting Party alleging expropriation shall refer the issue of whether the tax is an expropriation or whether the tax is discriminatory to the relevant Competent Tax Authority. Failing such referral by the Investor or the Contracting Party, bodies called upon to settle disputes pursuant to Article 26(2)(c) or 27(2) shall make a referral to the relevant Competent Tax Authorities;
• (ii) The Competent Tax Authorities shall, within a period of six months of such referral, strive to resolve the issues so referred. Where non-discrimination issues are concerned, the Competent Tax Authorities shall apply the non-discrimination provisions of the relevant tax convention or, if there is no non-discrimination provision in the relevant tax convention applicable to the tax or no such tax convention is in force between the Contracting Parties concerned, they shall apply the non-discrimination principles under the Model Tax Convention on Income and Capital of the Organisation for Economic Cooperation and Development;
• (iii) Bodies called upon to settle disputes pursuant to Article 26(2)(c) or 27(2) may take into account any conclusions arrived at by the Competent Tax Authorities regarding whether the tax is an expropriation. Such bodies shall take into account any conclusions arrived at within the six-month period prescribed in subparagraph (b)(ii) by the Competent Tax Authorities regarding whether the tax is discriminatory. Such bodies may also take into account any conclusions arrived at by the Competent Tax Authorities after the expiry of the six-month period;
• (iv) Under no circumstances shall involvement of the Competent Tax Authorities, beyond the end of the six-month period referred to in subparagraph (b)(ii), lead to a delay of proceedings under Articles 26 and 27.