Three of the government's biggest remaining budget tax bills have cleared the House of Representatives, putting the minimum tax on discretionary trusts, a start-up investor CGT discount and an R&D overhaul in the Senate's hands. With a Senate committee due to hold hearings this week and Labor reportedly aiming for passage in the third week of November, Business owners, trustees and founders have only weeks to understand what may change.

What passed the House on 29 October

On Thursday 29 October 2026, three bills passed the House at third reading and were sent to the Senate.

They are the Treasury Laws Amendment (Tax Reform No. 3) Bill 2026, the Income Tax Rates Amendment (Minimum Tax on Discretionary Trusts) Bill 2026, and the Treasury Laws Amendment (Tax Reform No. 4) Bill 2026.

Passing the House is a milestone, but it is not law. None of these measures takes effect unless the Senate also passes the bills and they receive Royal Assent. The government does not control the Senate in its own right.

The trust tax and housing follow-ups

Tax Reform No. 3 and the companion rates bill carry the proposed minimum tax on discretionary trusts. As introduced, the minimum tax would start on 1 July 2028, with three years of rollover relief available from 1 July 2027.

The same bill contains the second Tranche of the CGT changes, including rules for trusts, and a definition of a "new residential dwelling" for the negative gearing changes, along with exemptions for affordable and public housing, according to the Treasurer's second reading speech. It also carries transitional relief for Payday Super.

The trust measure is politically contested. One Nation has pledged to scrap it, and the government still needs the Greens, who have raised concerns about an exemption for private school fees.

The scale of the trust measure is one reason it has drawn so much attention. Treasury has estimated that about 350,000 small businesses used a discretionary trust in 2022-23 and that about 210,000 trusts would pay more. The measure is expected to raise about $4.5 billion.

The political framing differs sharply. Treasurer Jim Chalmers has said fewer than 10% of small businesses will be affected, while Opposition Senator Michaelia Cash argues the measure taxes small business twice.

Industry groups have also put forward much larger estimates of the advice and restructuring costs involved in complying. Those estimates have not been independently modelled and remain unverified until the groups publish their workings.

Submissions to the Senate inquiry closed on 29 October, and the committee's hearings are expected to test both the Revenue case and the compliance burden before senators decide how to vote.

The start-up, R&D and PAYG package

Tax Reform No. 4 is a broader business package. The package includes a 50% CGT discount for eligible start-up investors, simplification of the R&D tax incentive and changes to Venture Capital rules.

It would also introduce optional monthly PAYG instalments, while allowing the Commissioner to require monthly instalments from some non-compliant entities. Phased changes to the Fringe Benefits tax treatment of electric cars are also included.

The R&D changes are proposed to start on 1 July 2028, according to the government's second reading speech.

The monthly instalment option is one of the more practical changes for small and medium businesses that already pay PAYG instalments quarterly.

Hypothetical example: a company expects to pay $36,000 in PAYG instalments over a year. Under quarterly instalments it would pay four amounts of $9,000. If it opted into monthly instalments, it would pay 12 amounts of $3,000.

The annual total is the same, $36,000, but the money leaves the business in smaller, more frequent amounts. For some businesses that may smooth cash flow; for others, more frequent lodgment and payment adds administration. The detail, including how instalment amounts are calculated, depends on the final legislation.

The measure is proposed, not law, and this example is illustrative only.

The Senate deals being discussed

Labor's reported target is to have the package through the Senate by the third week of November. That timetable has not been confirmed officially.

The Greens have reportedly sought to exclude fossil-fuel companies from R&D rebates, said to be worth about $350 million a year, and to extend the proposed 15-year refundable R&D period for biotech and high-tech firms.

Independent MP Monique Ryan has described the 10- and 15-year caps as arbitrary, while AusBiotech has warned that later-stage Clinical Trials could move offshore, the same reports said.

Any amendments agreed in the Senate would need to return to the House, which could affect the timing.

What the bills could mean now

For trustees, the key dates are in 2027 and 2028, but advice and modelling take time. Industry groups have raised concerns about compliance costs, restructuring, state stamp duty and how elections under the new regime would work.

For founders and investors, the start-up CGT discount and R&D changes could shape decisions on capital raising and research spending, but eligibility rules are still subject to the bill's passage and any amendments.

Key dates to watch

  • 5–6 November: Senate Economics Legislation Committee hearings into Tax Reform No. 3 and the trust rates bill are scheduled.
  • 13 November: the committee's report is due.
  • Third week of November: the government's reported target for Senate passage of the package.
  • 1 July 2027: proposed start of three-year rollover relief for discretionary trusts, if passed.
  • 1 July 2028: proposed start of the minimum tax on discretionary trusts and of the R&D changes.

Each of these dates depends on the bills passing the Senate in their current form. Watch for committee recommendations, crossbench amendments and any change to start dates.