28ZE(1)
The determination of a question referred to the tribunal under section 28ZA of this Act is binding on the parties to the referral in the same way, and to the same extent, as a decision on a preliminary issue in an appeal.
28ZE(2)
The determination shall be taken into account by an officer of the Board—
(a) in reaching his conclusions on the enquiry, and
(b) in formulating any amendments of the return required to give effect to those conclusions.
28ZE(3)
Any right of appeal under section 31(1)(a), (b) or (c) of this Act may not be exercised so as to reopen the question determined except to the extent (if any) that it could be reopened if it had been determined as a preliminary issue in that appeal.