I assume the Deputy is referring to the High-Income Individual’s Restriction. The restriction is designed to ensure that individuals with an adjusted income level of €400,000 or more (where the full restriction applies) pay an effective rate of Income Tax of approximately 30%. Where adjusted income is less than €400,000, a tapering approach ensures that there is a graduated application of the restriction, with the effective rate of Income Tax increasing.
A comprehensive analysis of the restriction is published on an annual basis. These reports are available on Revenue’s website at the link: http://www.revenue.ie/en/corporate/information-about-revenue/research/statistical-reports/high-income-earners-reports.aspx .
The latest full year for which information is available is 2017. I am advised by Revenue that in that year the average effective rate of income tax, for cases with income in excess of €325,000 per year to which the restriction applies, was already greater than 35%. The yield from increasing the effective rate by 5% (from 30% to 35%) for those earning in excess of €200,000, but less than €325,000, is tentatively estimated to be in the order of €1.5m.