The Canadian competent authority will apply pre-Fundy amorphous criteria in the context of reviewing a trust's residency under the Canada-US tie-breaker rule

The Fundy Settlement case established that the residence of a trust turns on where its central management and control is exercised.  However, where a trust is resident both in Canada and the United States under each jurisdiction's general rules, the Canadian competent authority, in an endeavour to resolve the trust's residency under Art. IV (4) of the Canada-US Convention, will consider such factors as the residency of the settlor and beneficiaries, the location of the trust property, and the reason the trust was established in its jurisdiction.  CRA also notes that Art. IV(4) only obliges the authorities to attempt rather than reach a resolution of the residency question.

As s. 4.3 of the Income Tax Conventions Act trumps the Convention, the Convention's tiebreaker rules cannot be applied where s. 94(3) deems a trust to be resident in Canada.

Neal Armstrong.  Summary of 11 October 2013 APFF Round Table Q. 3, 2013-049281 F (Dual residency of a trust) under Treaties - Art. 4.