959AA Chargeable persons: time limit on assessment made or amended by Revenue officer.
(1) Where a chargeable person has delivered a return for a chargeable period and has made in the return a full and true disclosure of all material facts necessary for the making of an assessment for the chargeable period—
(a) an assessment for that period, or
(b) an amendment of an assessment for that period,
shall not be made by a Revenue officer on the chargeable person after the end of 4 years commencing at the end of the chargeable period in which the return is delivered and—
(i) no additional tax shall be payable by the chargeable person after the end of that period of 4 years, and
(ii) no tax shall be repaid after the end of a period of 4 years commencing at the end of the chargeable period for which the return is delivered,
by reason of any matter contained in the return.
(2) Nothing in this section prevents a Revenue officer from, at any time, amending an assessment for a chargeable period—
(a) where the return for the period does not contain a full and true disclosure of all material facts necessary for the making of an assessment for that period,
(b) to give effect to a determination on any appeal against an assessment or against a determination to which section 949 applies,
(c) to take account of any fact or matter arising by reason of an event occurring after the return is delivered,
(d) to correct an error in calculation in the assessment, or
(e) to correct a mistake of fact whereby any matter in the assessment does not properly reflect the facts disclosed by the chargeable person,
and tax shall be paid or repaid (notwithstanding any limitation in section 865(4) on the time within which a claim for a repayment of tax is required to be made) where appropriate in accordance with any such amendment.
(3) Nothing in this section affects the operation of section 804(3),
>811, 811A or< 1048.