Section 100A reimbursement agreements: the family trust trap when retired parents are beneficiaries

Family discretionary trusts have been a mainstay of Australian small business and investment structures for decades. The trustee distributes income each year to a chosen mix of beneficiaries — typically family members across multiple generations — and the choice of recipient determines the marginal tax rate that applies to that share of income. For families with retired parents on low marginal rates and adult children on high marginal rates, distributing trust income to the parents has long been an effective way to manage the family's overall tax position. Where the parent genuinely receives and uses the funds for their own retirement, this is unobjectionable. But where the distribution to the parent is on paper only — with the funds redirected to the adult children, to the children's businesses, or back to the trust — section 100A of the Income Tax Assessment Act 1936 has a long-standing role in catching the arrangement (https://classic.austlii.edu.au/au/legis/cth/consol_act/itaa1936240/s100a.html, accessed 6 May 2026), and the ATO has been visibly active in its enforcement since releasing detailed guidance through Taxation Ruling TR 2022/4 and Practical Compliance Guideline PCG 2022/2.

The basic mechanism of section 100A is straightforward. Where a beneficiary is presently entitled to trust income, and that present entitlement arose from or in connection with a "reimbursement agreement" — broadly, an arrangement under which the economic benefit is provided to a different person — and a purpose of the agreement is the reduction of tax, section 100A treats the beneficiary as not being presently entitled. The trustee is then taxed under section 99A at the top marginal rate plus Medicare on the relevant share of trust income. The beneficiary's tax position is reset, and the trustee bears the tax cost. The provision exists to prevent income being funnelled through low-rate beneficiaries on paper while the actual economic enjoyment sits with higher-rate parties.

The principal carve-out from section 100A is the "ordinary family or commercial dealing" exclusion in section 100A(13). Section 100A does not apply where the agreement is one entered into in the course of ordinary family or commercial dealing. The boundary between an ordinary family dealing and a reimbursement agreement is fact-specific, and that boundary is the focus of the ATO's 2022 guidance. TR 2022/4 sets out the legal interpretation of section 100A and the meaning of "reimbursement agreement" and "ordinary family or commercial dealing" (ATO — TR 2022/4, https://www.ato.gov.au/law/view/document?DocID=TXR%2FTR20224%2FNAT%2FATO%2F00001, accessed 6 May 2026). PCG 2022/2 sets out a colour-coded risk framework — white, green, blue, and red zones — that practitioners use to assess specific arrangements (ATO — PCG 2022/2, https://www.ato.gov.au/law/view/document?DocID=COG%2FPCG20222%2FNAT%2FATO%2F00001, accessed 6 May 2026). The white zone covers entitlements arising before 1 July 2014 (where the ATO's compliance focus is generally limited), the green zone covers arrangements the ATO views as low risk and won't allocate compliance resources to in the absence of new information, the blue zone covers arrangements that don't fit cleanly into the other zones and warrant case-by-case consideration, and the red zone covers high-risk arrangements that will be subject to compliance action.

The classic retiree-related arrangement that attracts section 100A scrutiny has a specific shape. A family trust controlled by adult children — typically a corporate trustee with the children as directors and shareholders — distributes trust income each year to retired parents who have low marginal rates. The retired parents are beneficiaries on paper, the distributions appear in the parents' tax returns at low rates, but the funds don't materially change the parents' lifestyle or savings. Instead, the parents quickly gift the funds back to the children, the children's businesses, or directly to the trust. The economic benefit of the trust income flows to the higher-rate adult children, but the tax cost is calculated as if it had flowed to the lower-rate parents. This is a textbook section 100A scenario, and the ATO has been actively pursuing such arrangements since the 2022 guidance issued.

The legitimate retiree distribution looks materially different. The retired parent receives a trust distribution each year. The funds enter the parent's own bank account, mix with their other retirement income (Age Pension, super pension, dividends, interest), and are spent on the parent's actual retirement life — housing, food, healthcare, holidays, occasional gifts to grandchildren on the parent's own initiative. There is no pattern of redirection back to the children. There is no documentary evidence of a coordinated arrangement. There is no immediate gifting on receipt. The parent enjoys the economic benefit; the trust distributes income to a beneficiary who actually uses it. Section 100A does not apply to such arrangements, and the ATO's PCG places them in the white or green zone.

The distinguishing features between legitimate distribution and reimbursement agreement come down to several practical tests. Time delay matters: a genuine gift from a retiree to children or grandchildren typically follows trust distribution by many months or years, after the retiree has accumulated their own savings; a reimbursement agreement gift typically follows immediately. Pattern matters: a genuine gift is occasional and event-driven (grandchild's school fees, medical assistance, wedding); a reimbursement agreement gift is repeating and aligned with each distribution. Documentation matters: a reimbursement agreement may have prior correspondence, accounting records, or advice files indicating the arrangement; a genuine gift does not. Use of funds matters: a genuine retiree mixes the trust funds with their own and uses them generally; a reimbursement agreement keeps the funds segregated and traceable. The ATO uses these factors when assessing risk and reviewing specific arrangements.

A specific question that often arises in client conversations is whether a retired beneficiary can ever make a genuine gift to their children. The answer is yes, but the gift has to be exactly that — a genuine gift, made by the retiree on their own initiative, after the trust funds have become part of the retiree's ordinary financial position, not a pre-arranged redirection of trust income through the retiree's account. A retiree who has received trust distributions for ten years, accumulated personal savings, and decides to help a child with a deposit on a home is not engaged in a reimbursement agreement. A retiree who receives a $100,000 trust distribution and writes a $100,000 cheque to the children the next week, repeatedly each year, is. The line is fact-specific, and the documentation supporting the genuine flow matters.

The Centrelink interaction layers additional complexity for Age Pensioner retirees who are family trust beneficiaries. Trust distributions are generally assessable as income for the Age Pension income test, reducing the pension where they exceed the income free area (FY25-26 single $218 per fortnight, couple combined $380 per fortnight). Where the retiree has effective control over the trust (a controller in Centrelink terms), the trust assets and income may be attributed to the retiree under the private trust attribution rules in DSS Social Security Guide section 4.12 (https://guides.dss.gov.au/social-security-guide/4/12, accessed 6 May 2026). And where the retiree gifts the distribution back to children, the gifting deprivation rules apply: gifts above $10,000 in a single financial year or $30,000 over five years are deemed to remain the retiree's asset for five years (DSS Social Security Guide 4.1.1.30 — Gifting & deprivation, https://guides.dss.gov.au/social-security-guide/4/1/1/30, accessed 6 May 2026). So a retiree receiving $80,000 distributions and gifting $60,000 back creates compound issues — section 100A risk on the trust side, and Age Pension complications on the Centrelink side, with the gifted funds still counted as the retiree's assets for years afterward.

The practical advice work for families with established trust arrangements involving retiree distributions is to map the actual flow of funds, assess where the arrangement sits on the PCG colour-zone framework, and decide whether to restructure. For arrangements that fall in the red zone — where the redirection back to children is documented or pattern-evident — restructuring is generally the rational response: change the distribution pattern, accept that future trust income will be taxed at higher rates if it goes to children directly, and stop the redirection. The cost of restructuring is real (more tax going forward) but smaller than the cost of an ATO challenge with retrospective application across many years. For arrangements in the white or green zones — where the retiree genuinely receives and uses the funds — the discipline is to maintain documentation that supports the genuine flow: bank account ownership, expense records, evidence of the retiree's own use of funds, time delays before any gifts. Section 100A risk is ongoing, year on year, and an annual review with the family's accountant is appropriate.

What do worked planning examples show?

These two cases show how section 100A risk lands differently for different family-trust retiree positions. Illustrative only — not personal advice — using FY25-26 figures.

Case 1 — Robert and Helen, both 76, retired beneficiaries of a family trust controlled by their three adult children. The trust holds investment property and shares generating around $300,000 in net income each year. For the past 15 years, the trust has distributed $90,000 to Robert and $90,000 to Helen, with the remainder distributed to the children. Robert and Helen each year transfer the bulk of their distribution back to the trust or to the children's businesses, retaining only enough for "household expenses." On these facts, the arrangement sits in the red zone of PCG 2022/2: there is a clear pattern of redirection, the funds don't materially change Robert and Helen's lifestyle, and the children are the economic beneficiaries — exactly the fact pattern the ruling targets. The rational pathway is to engage the family's tax adviser for a section 100A risk assessment, restructure the distribution pattern going forward (distribute directly to the children, accept higher-rate tax under section 99A or distribute to a corporate beneficiary), and consider whether a voluntary disclosure of historical exposure is appropriate — coordinated with the broader voluntary-disclosure framework covered in articles/2026-05-05-voluntary-disclosure-centrelink if Centrelink reporting also needs to be addressed. The trap to avoid is continuing the historical pattern in the hope that the ATO won't notice — the 2022 guidance signalled active compliance interest, and pattern-evident arrangements are exactly the targets.

Case 2 — Margaret, 71, beneficiary of a family trust controlled by her son. Margaret receives an annual trust distribution of $40,000, which is paid into her own bank account and used for her retirement expenses — household bills, holidays with grandchildren, dental work, contributions to a community organisation she cares about. She has not gifted material amounts to her son in the past five years; an occasional birthday or Christmas gift of a few thousand dollars is the pattern. On these facts, the arrangement sits in the white or green zone of PCG 2022/2: Margaret is the genuine economic beneficiary, the funds change her lifestyle, no pattern of redirection. The rational pathway is to maintain the documentation discipline — bank statements showing receipt and expenditure, expense records, no immediate large gifts back — and continue the arrangement. She also needs to ensure the $40,000 distribution is reported correctly to Centrelink for the income test (which may reduce any part Age Pension she receives), and that any gifts she makes stay below the $10,000 single year / $30,000 five-year deprivation thresholds. The trap to avoid is becoming complacent about documentation; if challenged later, the evidence of genuine flow needs to be available.

For retired beneficiaries of family discretionary trusts, section 100A is the rule that distinguishes legitimate distribution from arrangement-driven income shifting. The 2022 ATO guidance has not changed the law, but it has materially shifted the compliance landscape: arrangements that were quietly tolerated for years are now actively reviewed, and the colour-zone framework provides a clear lens for self-assessing risk. For families with patterns of distribution-and-redirection, the conversation needs to move from "this is how we've always done it" to "what does the structure need to look like from here." For families with genuine retiree benefit flow, the conversation is about maintaining the documentation that supports the position. Either way, an annual review with the family's tax adviser is the discipline that keeps the arrangement out of trouble.

Sources

• classic.austlii.edu.au — S100a
• Australian Taxation Office (ATO) — Document
• Australian Taxation Office (ATO) — Document
• DSS Social Security Guide
• DSS Social Security Guide