(1) Where a chargeable person, or a person to whom section 959T applies, delivers a return but does not include a self assessment in the return, a Revenue officer, subject to section 959AA(1) -
(a) shall, where section 959S applies, and
(b) may, in any other case,
make the self assessment in relation to the chargeable person.
(2) Where a self assessment is made under this section, a Revenue officer shall give notice of the assessment in accordance with section 959E.
(3) Any self assessment made by a Revenue officer under this section shall be deemed to be a self assessment made by the chargeable person and references in the Acts to the self assessment of a chargeable person shall be treated as including a self assessment made under this section.