Section 14 (inserted by the Act of 1978) of the Principal Act is hereby amended -
(a) by the substitution of the following subsection for subsection (1):
"(1) A person who satisfies the Revenue Commissioners that -
(a) taking one period with another, not less than 90 per cent. of such person's turnover is derived from taxable supplies to persons who are not registered persons, or
(b) the total consideration which such person is entitled to receive in respect of such person's taxable supplies has not exceeded and is not likely to exceed £250,000 in any continuous period of twelve months,
may, in accordance with regulations, be authorised to determine the amount of tax which becomes due by such person during any taxable period (or part thereof) during which the authorisation has effect by reference to the amount of the moneys which such person receives during such taxable period (or part thereof) in respect of taxable supplies.",
and
(b) in subsection (2) -
(i) by the deletion of "