Mr. Brown is the director of Success Limited, a company carrying on business in Hong Kong. In January 2023, Brown notified Success Limited that he wished to retire from his office. Brown was persuaded to stay in office, and received a "compensation payment for agreeing not to retire" of $800,000 in March 2023.

In May 2023, Brown received his composite tax return (Form BIR 60) for the year of assessment 2022/23, and asked his tax consultant for advice about the taxability of the payment of $800,000. He was told that the payment might not be taxable, and as the Inland Revenue Department would not know about it, he did not need to report the sum as assessable income. Brown acted on this advice.

In August 2023, Brown urgently flew to Belgium to take care of his mother, who was critically ill. When he returned to Hong Kong on 1 October 2023, he discovered that a salaries tax assessment for the year of assessment 2022/23 had been issued to him, dated 20 August 2023. The assessment included the payment of $800,000. He also received a notice issued under s.51(3) of the Inland Revenue Ordinance by the assessor, asking him to explain the omission of income from his salaries tax return.

Required:

1. State the conditions that must be satisfied before an objection against the salaries tax assessment can be lodged and advise Brown whether a valid objection can be lodged in his case. (2 marks)