From www.dbalawyers.com.au: Streaming different types of income to beneficiaries in discretionary trusts requires express authorization in the trust deed, otherwise, the ATO expects income to be distributed proportionately.
Trustees can have the discretion to include or exclude certain amounts from distributable income, but this power must also be clearly stated in the deed.
Trust deeds that were established before 2012 should be reviewed for adequate streaming provisions, and amendments may be necessary to ensure compliance with current tax strategies.