(1) In this section 'neglect' means negligence or a failure to give any notice, to make any return, statement or declaration, or to produce or furnish any list, document or other information required by or under the Acts.

(2) For the purposes of subsection (1), a person shall be deemed not to have failed to do anything required to be done within a limited time if the person did it within such further time, if any, as the Revenue Commissioners or Revenue officer concerned may have allowed and, where a person had a reasonable excuse for not doing anything required to be done, the person shall be deemed not to have failed to do it if the person did it without unreasonable delay after the excuse had ceased.

(3) Notwithstanding sections 959AA and 959AB, where a Revenue officer has reasonable grounds for believing that any form of fraud or neglect has been committed by or on behalf of a person in connection with or in relation to tax due for a chargeable period, a Revenue officer may, at any time, make a Revenue assessment on that person for the chargeable period.

(4) An assessment to which this section applies shall be made by a Revenue officer in such sum as, according to the best of the officer's judgment, ought to be charged on the person involved.