Section 4A: inserted, on 1 April 2015, by section 8 of the Child Support Amendment Act 2013 (2013 No 12).
Section 4A: amended, on 25 February 2016, by section 6 of the Taxation (Annual Rates for 2015–16, Research and Development, and Remedial Matters) Act 2016 (2016 No 1).