(1) Where the inspector or such other officer as the Revenue Commissioners may nominate to exercise the powers conferred by this section (in this section referred to as ‘other officer’) has reason to believe that -
(a) a return made under section 985G does not include the total amount of tax due for the relevant income tax month, or
(b)a return should have, but has not been, made under section 985G for an income tax month,
then, without prejudice to any other action which may be taken, the inspector or other officer -
(i) may make an assessment in one sum of the total amount of tax which in his or her opinion should have been paid in respect of the income tax month, and
(ii) may serve notice on the employer specifying -
(I) the total amount of tax so assessed,
(II) the total amount of tax (if any) remitted by the employer in relation to the income tax month, and
(III) the balance of tax remaining unpaid.
(2) Where the inspector or other officer has reason to believe that the amount
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