As respects the year of assessment 2005 and subsequent years of assessment, section 950 of the Principal Act is amended, in the definition of "chargeable person" in subsection (1), by substituting the following for paragraph (a):

"(a) whose only source or sources of income for the chargeable period is or are sources the income from which consists of emoluments to which Chapter 4 of Part 42 applies, but for this purpose a person who, in addition to such source or sources of income, has another source or other sources of income shall be deemed for the chargeable period to be a person whose only source or sources of income for the chargeable period is or are sources the income from which consists of emoluments to which Chapter 4 of Part 42 applies if the income from that other source or those other sources is taken into account in determining the amount of his or her tax credits and standard rate cut-off point for the chargeable period applicable to those emoluments, and, for the purposes of deciding whether such income should be so taken into account, the Revenue Commissioners may have regard to the amount for that, or any previous, chargeable period of the income of the person from that other source or those other sources before deductions, losses, allowances and other reliefs,".