Sole trader to company: when the switch makes sense and what actually changes

The triggers that actually matter

Most sole traders who ask about incorporating are reacting to one of four things, and it is worth naming which one, because it changes what the switch is actually for. The first is liability: a sole trader is personally on the hook for every business debt and, depending on the work, every claim against it — there is no legal separation between the person and the business. A company is a distinct legal entity under the Corporations Act 2001, so a claim against the business is generally a claim against the company, not against the director's house.

The second is the tax rate crossover. A sole trader's business profit is taxed at individual marginal rates, which climb as income rises. A company pays a flat rate on its taxable income — 30% generally, or 25% if it qualifies as a base rate entity (broadly, aggregated turnover under $50 million with no more than 80% of assessable income being passive income) — for the 2025-26 income year, per the ATO's company tax rate schedule. Once profit consistently sits above the point where the individual marginal rate exceeds the company rate, retaining earnings inside a company rather than drawing them all out personally can matter — but this is a genuine "it depends" that turns on how much is drawn out as salary or dividends, franking credits, and the individual's other income, and it is exactly the kind of call that sits with a registered tax agent, not a rule of thumb.

The third is hiring. Nothing legally stops a sole trader from employing staff, but growth plans that involve building a team, offering equity-like incentives, or scaling past what one person can bill often arrive alongside a structural rethink anyway, because the two conversations happen at the same time. The fourth is investors or a future sale: outside parties putting capital in almost always want shares in a company, not a share of an individual's trading income, and a business built to be sold is easier to sell as a company with a clean asset register than as a sole trader's undifferentiated activity.

None of these triggers, on their own, means incorporating is the right call this quarter. They are the reasons the conversation starts. Whether it is the right year to act on it is a decision for the founder and their accountant, weighing the compliance cost of running a company against the benefit being chased.

The CGT rollover that can apply — and its conditions

Moving business assets from a sole trader into a company is, in tax terms, a disposal — the sole trader is transferring assets to a separate legal entity, which is ordinarily a CGT event. Subdivision 122-A of the Income Tax Assessment Act 1997 provides rollover relief for exactly this transition: an individual can choose to defer the capital gain (or loss) that would otherwise arise on transferring assets to a wholly-owned company, per the ATO's guidance on rollover and restructure.

The conditions are specific and worth naming plainly rather than assuming they are automatically met. The individual must transfer the asset (or assets) to a company; in exchange, they must receive only shares in that company (no other consideration, or the rollover can fail or apply only partially); immediately after the transfer, the individual must own all the shares in the company; and the company must not be an exempt entity. Where all shares are not held solely by the transferring individual after the transfer — for example, a co-founder is issued shares from day one — the rollover as it applies to a sole individual does not fit cleanly, and the structuring question becomes more involved.

The rollover is a choice, not an automatic outcome, and choosing it defers the gain rather than eliminating it — the company effectively inherits the asset's cost base, so the gain can crystallise later on a future disposal. Whether to elect it, how it interacts with the small business CGT concessions, and how it is reported are all determination calls for the tax agent handling the transfer, working from a clear list of what assets are actually moving and what they are worth.

The record-keeping split: the sole-trader books close, the company books open

The most common mistake after incorporating is not a missed registration — it is letting the two sets of books blend into one continuous ledger, because the day-to-day work looks identical from the inside. It is not the same entity, and the books have to say so.

The sole-trader books close at the transition date: final BAS lodged against the old ABN, final reconciliation done, and that ledger archived as a closed record, not carried forward as opening balances typed into a new file. The company's books open fresh from the transition date, with the assets and any rollover-affected cost bases the tax agent has confirmed, and its own bank feed, its own GST registration, and its own BAS cycle from day one.

Where the two commonly get blended by accident: a supplier still invoicing the sole trader's ABN weeks after the company started trading, business banking that keeps running through the old personal-linked account because closing it felt like a later problem, or a bookkeeper importing the old ledger's chart of accounts wholesale instead of setting up the company's own. Any of these leaves an entity boundary that exists on paper at ASIC and the ABR but not in the actual transaction record — which is precisely the gap a future audit, sale, or investor's diligence review will find first.