A common structure for tradespeople and some professionals is a spousal partnership, one partner does the hands-on work (the plumbing, the electrical work, the consulting), while the other handles the books, the phones, the invoicing, and the admin. Profits are then split according to thepartnership agreement, often 50/50, even though one partner clearly generates most of the income. The ATO has recently updated its guidance on when this arrangement is safe from challenge under Part IVA, the general anti-avoidancerule, and it's largely good news, provided the partnership is genuine.

The ATO's position on "spousal partnerships"

The ATO has long accepted that a genuine spousal partnership can split profits according to the partnership agreement, without that being treated as tax avoidance, even where one spouse generates almost all of the income. The reasoning is straightforward: forming a partnership and sharing profits under the terms partnership law prescribes isn't "contrived," it's simply how a partnership works. Recent ATO guidance reaffirms this, stating that the mere fact that spouses run a business as a partnership and split profits in a tax-advantageous way isn't, on its own, enough to conclude they've structured things purely to get a tax benefit.

There's an important qualifier, though: if a partnership has features that only really make sense as a way of obtaining a tax benefit, that conclusion can change. The ATO's own example is a partnership where one partner does no work, contributes no capital, and takes no part in running the business; that kind of imbalance raises real questions.

Where the risk for "spousal partnerships" actually sits

For a genuine, active mum and dad partnership, splitting income according to the partnership agreement is low risk. The main situations where Part IVA becomes a live issue are as follows:

Changing the profit split year to year, especially around other tax events

Partners can vary their profit-sharing arrangement, but if a change happens to coincide with, say, one spouse having an unusually high income year elsewhere (such as a capital gain), and the partnership split is adjusted to shift more income to the other spouse with no real commercial reason for the change, that variation is exposed to Part IVA. Genuine, unrelated parties vary profit splits for commercial reasons all the time; the risk is specifically where the timing and rationale look tax-motivated within a family group.

Restructuring into a partnership from a sole trader

If a sole trader brings their spouse in as a partner, particularly where partof the business is effectively transferred to the spouse, the ATO will look separately at whether that restructure itself was done for a genuine commercial purpose or mainly to access a tax benefit, especially where CGT small business concessions reduce the cost of doing so.

A question mark over professional (rather than trade) partnerships

The ATO's traditional comfort with mum and dad partnerships developed mainly around tradespeople. There's some uncertainty about whether the same reasoning extends cleanly to partnerships built around professional services, that is, accounting, consulting, IT, and similar. Given the ATO's broader stance on retaining or splitting professional income (reflected in related guidance for larger professional firms), professionals considering this structure should proceed carefully. An alternative worth considering is operatings olely as the equity holder and employing your spouse for admin work, rather than making them a partner; this still allows a deduction for their salary and super, without wading into the partnership uncertainty.

What makes a partnership "genuine" in the first place?

None of the above matters if the partnership isn't genuine to begin with, and a partnership that isn't genuine is squarely open to ATO challenge regardless of Part IVA. The ATO looks at a range of factors, no single one of which is essential on its own, but which together build the picture:

• A clear intention to act as partners, ideally backed by a written partnership agreement

• Joint ownership of business assets and joint liability for business debts; partners are on the hook personally, not just to the extent of partnership property

• Both partners genuinely involved in the business, not just one running it while the other exists as a name on paper

• A registered business name in both partners' names

• A joint business bank account that both partners can operate

• Shared capital contributions to the business

• Profits and losses actually distributed as the agreement specified

• Proper business records; account books, meeting minutes

• Public-facing recognition of the partnership; invoices, letterhead, tenders, and lodgments all reflecting the partnership rather than one individual

The ATO has previously found against taxpayers where the paperwork told a different story to the partnership claim; for example, where BAS lodgments were made under one spouse's individual ABN and there was no partnership tax file number on record.

The financial upside of getting it right

The tax benefit of a genuine partnership structure can besignificant, simply because splitting income between two people generally results in less combined tax than concentrating it all with one, given Australia's progressive tax rates. As an illustration: a plumber earning $250,000 net income who splits it evenly with a genuine partner-spouse retains meaningfully more combined after-tax income as a family unit than if the same income were taxed entirely in the tradesperson's own hands as a sole trader, often tens of thousands of dollars more per year, depending on the numbers involved.

The takeaway

If you're running a business with your spouse and splitting profits, the critical question isn't really about Part IVA at all; it's whether the partnership is genuine in substance, not just on paper. Get that right, with proper documentation and a partnership that actually operates the way it says it does, and the ATO's own guidance gives you comfortable room to split income according to the agreement. Get it wrong, and no amount of PartIVA analysis will save an arrangement the ATO doesn't accept as a real partnership in the first place.

This article is general information only and does not constitute tax advice. Whether your arrangement qualifies as a genuine partnership, and whether any profit-split variation carries Part IVA risk, depends on your specific circumstances. Contact Causbrooks to review your partnership structure and documentation.