111. Assessment of tax due.
(1) Where, in relation to any period, the inspector of taxes, or such other officer as the Revenue Commissioners may authorise to exercise the powers conferred by this section (in this section referred to as "other officer"), has reason to believe that an amount of tax is due and payable to the Revenue Commissioners by a person in any of the following circumstances:
(a) the total amount of tax payable by the person, including tax (if any) payable in accordance with section 108C(3), 109A(4) or 91J(10)(b), was greater than the total amount of tax (if any) paid by that person;
(b) the total amount of tax refunded to the person in accordance with section 99(1) was greater than the amount (if any) properly refundable to that person;
(c) an amount of tax is payable by the person and a refund under section 99(1) has been made to the person;
(d) the total amount of tax refunded to the person in accordance with an order under section 103 was greater than the amount (if any) properly refundable to that person,