15(1)Any question which arises as to the manner in which the apportionment under any of paragraphs 11 to 14 above is to be made shall be determined, for the purposes of the tax of the parties concerned—U.K.
(a)in a case where one body of General Commissioners have jurisdiction with respect to all the parties concerned, by those Commissioners, unless the parties concerned agree that it shall be determined by the Special Commissioners;
(b)in a case where more than one body of General Commissioners have jurisdiction with respect to the parties concerned, by such of those bodies of General Commissioners as the Commissioners of Inland Revenue may direct, unless the parties concerned agree that it shall be determined by the Special Commissioners; and
(c)in any other case, by the Special Commissioners.
(2)The Commissioners by whom the question falls to be determined shall make the determination in like manner as if it were an appeal except that the parties concerned shall be entitled to appear and be heard by the Commissioners or to make representations to them in writing.
(3)In this paragraph, references to the parties concerned are to the persons between or amongst whom the apportionment in question falls to be made.