Sole trader, partnership or company? A practical guide for Australian startup founders on choosing the right business structure.
One of the first decisions any Australian founder makes is choosing a business structure. It sounds administrative, but it directly affects your personal liability, how you pay tax, whether you can raise capital, and how cleanly you can bring on co-founders or exit down the track. There is no universally correct answer. The right structure depends on what you are building, how much risk you are taking on, and where you want to end up.
This article breaks down the three most common structures for startups: sole trader, partnership, and company (Pty Ltd). We cover when each one makes sense, the real costs, the key risks, and the questions you should be asking before you commit.
Sole trader: the starting line
A sole trader is the simplest structure available. You and the business are legally the same entity. There is no separation between your personal assets and the business. You register an ABN for free through the Australian Business Register, and you are ready to trade. No ASIC registration is required unless you want to trade under a name other than your own (in which case you register a business name with ASIC for $45 per year or $105 for three years).
All business income flows straight into your personal tax return and is taxed at your marginal rate. For the 2025/26 financial year, the top marginal rate is 45% (plus 2% Medicare levy) for taxable income above $190,000. You can access the small business CGT concessions and the $20,000 instant asset write-off (extended through 30 June 2026).
The trade-off is unlimited personal liability. If the business is sued or cannot pay its debts, creditors can pursue your house, car, savings, and any other personal assets. There is no legal wall between you and the business.
When a sole trader structure makes sense:
• You are testing a business idea before committing significant capital.
• You are freelancing, consulting, or contracting as a one-person operation.
• The business carries low risk (no employees, no significant debts, no physical premises).
• You want to keep setup and compliance costs as close to zero as possible.
If you are building something with real growth ambitions, a sole trader structure will likely become a constraint quickly. You cannot issue shares, grant options, or bring in investors without restructuring.
Partnership: shared effort, shared risk
A partnership exists when two or more people carry on a business together with a view to profit. It does not require formal registration (beyond an ABN), but it is strongly advisable to have a written partnership agreement in place before you start trading.
Partnerships are governed by state and territory partnership legislation (for example, the Partnership Act 1892 (NSW)). The partnership itself is not a separate legal entity, which means the partners personally own the assets and bear the liabilities of the business. Each partner reports their share of partnership income on their individual tax return and pays tax at their personal marginal rate.
The biggest risk in a partnership is joint and several liability. This means each partner can be held personally responsible for 100% of the partnership's debts and obligations, not just their proportionate share. If your partner signs a contract that goes bad, or takes on debt the business cannot repay, creditors can come after you personally for the full amount.
There is also agency risk: each partner can generally bind the partnership in the ordinary course of business. If your partner makes a commitment to a supplier or a customer, you can be on the hook for it, even if you did not know about it or agree to it.
When a partnership might work:
• Two professionals with complementary skills want to collaborate on a low-risk, service-based venture.
• You are running a short-term project or joint venture where a full company structure would be overkill.
• Both parties understand and accept the liability exposure, and you have a comprehensive partnership agreement covering decision-making authority, profit sharing, capital contributions, restraint of trade, dispute resolution, and exit.
Our view: for most startups with genuine growth ambitions, a partnership structure is not the right fit. The liability exposure is too broad, the ability to raise capital is too limited, and the governance framework is too informal. If there are two or more founders, a Pty Ltd with a shareholders agreement is almost always the better path.
Company (Pty Ltd): the startup standard
A proprietary limited company (Pty Ltd) is a separate legal entity. It owns its own assets, incurs its own debts, and can sue or be sued in its own name. This is the structural separation that sole traders and partnerships do not have.
The key advantage for founders is limited liability. Shareholders are generally only liable for the amount unpaid on their shares. If the company fails owing creditors $500,000 and you paid $1 for your shares, your exposure is limited to that $1 in most circumstances. Directors can still face personal liability for insolvent trading, breaches of directors' duties, or personal guarantees, but the baseline protection is significantly better than a sole trader or partnership.
Companies are taxed at a flat rate of 25% for base rate entities (those with aggregated turnover under $50 million and meeting the passive income test). This compares favourably with personal marginal rates, which reach 45% (plus Medicare levy) above $190,000. Companies can retain profits, manage the timing of dividend distributions, and structure salary and dividend payments to optimise the overall tax position.
Importantly, a Pty Ltd structure allows you to issue shares, grant options, raise capital through SAFE notes or equity rounds, and implement an ESOP under Division 83A of the Income Tax Assessment Act 1997 (Cth) and the Corporations Act 2001 (Cth). None of this is possible as a sole trader or partnership.
The costs are higher:
• ASIC registration fee: $611 (2025/26).
• ASIC annual review fee: $329 per year.
• Director identification number: free, but mandatory.
• Accounting and tax compliance: typically $1,000 to $2,500 per year for a small company.
• Legal setup (constitution, shareholders agreement, founder vesting): varies, but budget $2,000 to $5,000 for a proper job.
You also need to maintain company registers, lodge annual returns, hold and document director resolutions, and comply with the Corporations Act on an ongoing basis. It is more work than a sole trader, but it is the cost of building on a proper foundation.
The comparison at a glance
Common mistakes founders make
Starting as a sole trader "to save money" and restructuring later. Restructuring from a sole trader to a company involves transferring assets, contracts, IP, and registrations. It can trigger CGT, stamp duty, and GST consequences. It is almost always cheaper to set up the right structure from day one.
Running a partnership without a written agreement. Without a partnership agreement, the default rules under state partnership legislation apply. These may not reflect what you actually agreed on. Disputes about profit sharing, authority, and exit become significantly harder (and more expensive) to resolve.
Assuming a company means zero personal risk. Limited liability is not absolute. Directors can be personally liable for insolvent trading under section 588G of the Corporations Act 2001 (Cth), for breaches of directors' duties (sections 180 to 184), and where they have given personal guarantees to banks or landlords. Limited liability protects you from general creditors, not from your own misconduct.
Ignoring the shareholders agreement. A company without a shareholders agreement is like a partnership without a partnership deed. If there are two or more founders, you need a shareholders agreement covering equity splits, vesting, decision-making, drag-along and tag-along rights, anti-dilution, IP assignment, and dispute resolution. The replaceable rules in the Corporations Act are not sufficient for a startup.
Questions to ask before you choose
• Am I building something I intend to scale, or is this a solo services business?
• Will I need to raise external capital at any point?
• Am I taking on risk that could put my personal assets in jeopardy (employees, leases, significant debts)?
• Do I have co-founders, and if so, how will we document equity, roles, and exit?
• What is the long-term plan: build and sell, build and hold, or something else?
• Have I spoken to a lawyer and an accountant before committing to a structure?
If the answer to any of the first four questions is yes, a Pty Ltd company is almost certainly the right starting point.
How Zed Law can help
Zed Law works with founders and growing businesses across Australia to get their structure right from day one. We handle company incorporations, constitutions, shareholders agreements, founder vesting arrangements, ESOP design, and partnership agreements. We also advise on restructuring from sole trader or partnership to company where the business has outgrown its original structure. Our approach is practical, direct, and built around what actually matters for your business stage.
Contact Zed Law at hello@zed.law to arrange a consultation.
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Disclaimer: This article is intended as general information only and does not constitute legal or tax advice. The information in this article is current as at March 2026. Specific advice should be obtained in relation to your particular circumstances.
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