Investing in a portfolio investment entity (PIE) could affect your other Inland Revenue responsibilities. It's less likely to have an effect if the income is from a locked-in PIE (KiwiSaver, retirement saving scheme or superannuation fund).
Income from a locked-in PIE will not affect your Working for Families Tax Credits or your student loan repayment obligations. Other PIE income will affect your Working for Families Tax Credits and should be included in the Adjust your income - IR215 form.
Your child support payments are not affected if your PIE income does not have to be included in your income tax assessment.
If you have mistakenly included income from a locked-in PIE in your income tax assessment, you can exclude it from your income again by completing the IR215.