Effective Cause of Sale in Queensland: How Courts Decide Who Earned the Commission
A seller switches agents mid-campaign. A buyer you showed through three open homes signs a contract six weeks later with a competitor agency. The seller insists they found the buyer themselves. Every agent working open listings or multi-agency appointments has faced a version of this scenario — and the question is always the same: who actually earned the commission?
The answer in Queensland turns on one of the most litigated concepts in real estate law: effective cause of sale. Understanding how courts apply this test — and what conduct either protects or destroys your claim — is not optional knowledge for a practising agent. It is the difference between collecting your commission and funding someone else’s litigation.
The Statutory Foundation: What the Property Occupations Act Actually Says
The Property Occupations Act 2014 (Qld) (the POA) is the governing legislation for commission entitlement in Queensland. Section 89 of the POA provides that an agent may only seek to recover or keep an award for performance of an activity if they actually perform that activity — such as the sale of a property. This is the statutory hook on which every commission claim must hang.
If the exclusivity period has expired or the appointment is non-exclusive, the agent’s appointment is likely “open,” and section 20 of the POA will apply. That section makes commission entitlement conditional on the agent being the effective cause of the sale — not simply on having a valid Form 6 in the file.
Critically, the term “effective cause of sale” is not defined in the POA. The legislature left that work to the courts, and decades of common law — much of it directly applicable in Queensland — has filled the gap. What emerges is a fact-intensive inquiry that no statutory definition could cleanly capture.
The POA also contains important companion provisions. Section 88 provides that commission may only be claimed for actual amounts, and section 89 restricts recovery where there is no proper authorisation. Together, these provisions mean the effective cause question always operates within a framework that also demands a properly executed Form 6 appointment. An agent can be the undisputed effective cause of a sale and still lose their commission claim if their appointment document does not comply.
The Legal Test: More Than a Mere Cause
The foundational statement of the law comes from the High Court of Australia. In LJ Hooker Ltd v WJ Adams Estates Pty Ltd (1977) 138 CLR 52, Jacobs J set out a formulation that Queensland courts have applied consistently ever since. His Honour said that “effective cause” means more than simply “cause.” The inquiry is whether the actions of the agent really brought about the relation of buyer and seller, and it is seldom conclusive that there were other events which could each be described as a cause of the ensuing sale. The factual inquiry is whether a sale is really brought about by the act of the agent.
That framing has shaped every subsequent decision. To establish that an agent was the effective cause of sale, it is necessary for the agent to prove that there was a causal connection between the agent’s efforts and the completion of the transaction. That causal connection must be direct and operative — not incidental, not historical, not theoretical.
The High Court in the same case was also candid about the rough edges of this rule. Rightly or wrongly, the law as it has evolved has made the earning of an agreed commission an all-or-nothing affair, on one hand denying to agents any reward despite substantial labour on their part and on the other handsomely rewarding agents who with little effort manage to effect a sale. That frankness from the highest court in the land tells you something important: the effective cause test is not designed to ensure fairness in every case. It is designed to provide commercial certainty.
The notion of “effective cause” reflects the requirement expressed in a long line of cases that it is not enough that the engagement of the agent to find a purchaser or to introduce a purchaser was a step without the taking of which the sale would not have been effected. The courts have consistently said something more immediate is required.
Introduction Alone Is Not Enough
This is where many agents misunderstand their position — and where sellers have historically tried to exploit the gap.
In Queensland, simply introducing a buyer to a property is not enough to automatically entitle an agent to commission. The concept of effective cause requires that the agent’s actions must have directly contributed to the sale. This means the agent must play a significant role in facilitating the sale, rather than just showing the property or introducing a potential buyer.
The Queensland case of Rasmussen & Russo Pty Ltd v Gaviglio [1982] Qd R 571 remains one of the most instructive decisions on this point. In that case, the court held that the first agent did not establish a sufficient causal link between the buyer and seller, despite introducing the buyer to the property. The agent had arranged for an executed contract in relation to the purchase, but the contract was rescinded because the buyer was unable to obtain finance. Subsequently, another agent was appointed who arranged for the execution of a contract and assisted the buyer in obtaining finance where the buyer could not previously. In that case, the first agent was not the effective cause of the sale.
This is the scenario that catches agents out. You did the early work. You held the opens. You introduced the buyer. But if negotiations broke down, the buyer walked away, and a second agent then revived and converted the transaction — particularly by doing something qualitatively different, such as resolving a finance obstacle or restructuring the terms — courts may find the second agent was the effective cause, not you.
The opposite outcome is also possible, and agents need to understand both poles. Where an agent introduces a buyer, conducts all substantive negotiations, and the transaction ultimately completes even after some interruption, the courts may find that the agent’s initial work “flowed through” to the eventual contract. In Moneywood v Salamon, the vendor sought to exclude the agent from a subsequent contract. The vendor and purchaser executed a first contract procured by the agent, which was conditional on council approval of a rezoning application. Following council’s failure to rezone, the vendor rescinded the first contract and entered into a new contract with the same purchaser for a lesser sum for part of the land, which did not acknowledge the agent. In formulating the second contract, the vendor sought to retain as much of the benefits as possible from the first. The court found that the initial work done by the agent, including introducing the purchaser to the land, “flowed through” to the second contract.
The distinguishing factor between Gaviglio and Moneywood is whether the second transaction was genuinely independent, or whether it was built on the foundation the first agent laid.
How Courts Weigh the Evidence: The Whole of Circumstances
Courts do not apply a simple checklist. The effective cause inquiry is holistic and fact-specific. The court said that whether either or both agents involved with a potential sale was an effective cause of sale cannot be determined by simply comparing the amount of work done by each agent. Rather, the work done by each agent must be considered in the process of evaluating all of the circumstances which may have had some causal relationship with the sale.
On a practical level, the effective cause test depends on a number of factors — including whether, if another agent effected the eventual sale, the terms negotiated by the second agent were significantly different to those previously negotiated by the first agent.
The significance of this cannot be overstated. If Agent A introduced the buyer and negotiated an offer at $800,000, but the seller rejected it, and Agent B then sold the same property to the same buyer at $780,000 six weeks later — Agent A may have a much stronger claim than they think. The terms are similar, the buyer is the same, and the effort of Agent B in “closing” the deal may be characterised as building on Agent A’s groundwork rather than displacing it.
Conversely, if Agent B negotiated entirely different terms, brought in a completely different finance structure, restructured special conditions, or managed a materially different transaction timeline — the courts may see Agent B as the operative cause of that particular transaction coming to fruition.
The burden of proof lies with the agent seeking to recover the sales commission. The agent must convince the court that it was their ongoing efforts that influenced the buyer’s decision to purchase the property. This has practical implications for how agents document their work, which is addressed below.
When Agency Agreements Expire: The Post-Appointment Trap
One of the most common trigger points for effective cause disputes in Queensland is the period immediately after an exclusive agency ends. Even after the exclusive agency period has expired, an agent may still be entitled to commission if they were the effective cause of the sale. This occurs when the agent introduces a buyer who eventually purchases the property after the agency period ends. Courts in Queensland have upheld agents’ claims for commission in such cases, provided they can prove that their efforts directly contributed to the sale.
The Queensland Civil and Administrative Tribunal Appeal decision in West Property Solutions t/as Century 21 West Property Group v Lewis & Anor [2015] QCATA 42 and 66 illustrates both the risk and the protection. The Appeal Tribunal considered the Supreme Court of Queensland’s decision in Rankine & Ors v Rankine & Ors [1996] QSC 281, in which Justice Ambrose held that the real estate agent introduced the purchaser by calling public tenders and conducting negotiations which led to the sale. The Appeal Tribunal found that, in the same way, the agent in West had introduced the Bartletts to the property by advertising, holding open homes, and negotiating the terms of a contract.
The fact that the vendors paid for the advertising and went to the expense and trouble of engaging another agent were not relevant considerations. The Appeal Tribunal therefore found that the first agent introduced the buyers and was entitled to the commission.
Sellers who dismiss their exclusive agent and relist with another agency — only to see their property sell to a buyer the first agent introduced — can find themselves paying commission twice. Some sellers unwittingly expose themselves to multiple claims for commission by not taking into account that an agent may still be entitled to commission for a sale that takes place after expiry of the agent’s appointment if the agent was the effective cause of the sale. As an agent, knowing this principle protects your interests. As a listing agent explaining it to a vendor who wants to switch agencies, it is information you are obliged to give them.
The Multiple Effective Cause Scenario
The law does not always produce a single winner. In deciding whether the agent was the effective cause of sale, courts have referred to authorities which demonstrated that an agent may be the effective cause of sale whether it is the sole cause of the sale or an effective cause of sale among other causes.
The 2024 Queensland District Court decision of Podium Project Marketing Pty Ltd v B Global (Aust) Pty Ltd [2024] QDC 219 pushed this principle into new territory. In that case, the District Court of Queensland examined a real estate agent’s entitlement to commission in circumstances where it was engaged to sell residential lots in a development on the basis of an open listing and had engaged various entities to act as sub-agents to identify and secure buyers. The defendant property developer appointed the plaintiff sales agent as its non-exclusive agent for the sale of 60 lots pursuant to three Property Occupations Form 6 Appointments. Commission for the sale of each lot was $40,000 plus GST, 50% payable when a sale contract became unconditional and 50% at settlement.
As the case demonstrates, an agent may be regarded as the effective cause of sale in circumstances where it has not sourced or had any direct contact with the buyer, but its actions have constituted a causal link between the seller and buyer. The developer had authorised the use of sub-agents, and the agent’s organisational contribution — setting up the system through which buyers were identified — was sufficient to establish the causal link even without personal contact with each individual buyer.
This has significant implications for project marketing agents and principals who operate large-scale campaigns using referral networks or offshore buyer sourcing.
The Queensland Court of Appeal: Sunshine Group Australia Pty Ltd v Trappando Pty Ltd [2023] QCA 214
This 2023 Court of Appeal decision is worth examining in detail because it addressed several issues that regularly arise in commission disputes simultaneously.
In Sunshine Group Australia Pty Ltd v Trappando Pty Ltd [2023] QCA 214, the seller listed the property for sale with the agent. The Form 6 appointment, dated 15 January 2018, provided that it was a “continuing appointment” commencing on that date for an “open listing.” The list price was $12,000,000.
An outside party — Soh — claimed to have international buyers and sought a personal reward from a principal of the agency. In 2019, Anderson was approached by Victor Soh who said he had “international buyers” interested in the property. Soh, who was not a real estate agent, wished to be rewarded for any introduction of the buyer to the property. On 13 May 2019, Soh, Anderson, and the director of the seller entered into a Deed of Agreement whereby Soh was rewarded on a sale.
The seller attempted to use that Deed to argue Anderson was acting personally rather than as the agent’s representative, and therefore that the agent was not the effective cause. The Court of Appeal rejected this. The agent was the effective cause of sale, not Anderson in his personal capacity. The email correspondence in relation to the sale of property was all signed off by Anderson in his capacity as sales manager for the agent’s real estate business, and it was the agent who was the appointed real estate agent for the sale of the property by the relevant Form 6. The agent was also nominated as the seller’s agent in both contracts of sale, and the property was marketed by the agent — it was the means by which the buyer found the property.
The case reinforces a critical professional discipline: everything you do in connection with a listing must be done in your capacity as the appointed agent, not in your personal capacity. Informal side arrangements — even well-intentioned ones designed to incentivise referrers — can blur that line dangerously.
What Breaks the Causal Chain
Understanding what extinguishes a commission claim is just as important as understanding what creates one. Courts have identified several circumstances that break the causal connection between an agent’s efforts and the eventual sale.
A failed first contract, as in Gaviglio, is the clearest example — particularly where the failure stems from a fundamental deficiency (such as a buyer unable to obtain finance) and a second agent then resolves that exact deficiency to secure an entirely fresh contract. Where the second transaction is truly independent — different terms, different price, a second agent who did materially different work — the first agent’s causal chain is broken.
Abandonment of the transaction by the first agent also breaks the chain. In the NSW Court of Appeal decision of Emmons Mount Gambier Pty Ltd v Specialist Solicitors Network Pty Ltd [2005] NSWCA 117, a first agent introduced a potential buyer for a hotel, provided trading figures, secured an offer to purchase for $25 million, but the vendors sought $30 million, and after attempting to bridge the gap the agent ceased his efforts to bring about a sale. Between 2 September and 3 October 1996, a second agent brokered a purchase by the potential buyer for $29.7 million. The court held that the first agent had not proven that his efforts were an effective cause of the sale. Ceasing active pursuit of the transaction — withdrawing from negotiations, failing to follow up — severs the thread.
Substantial variation in the terms of the ultimate transaction, relative to anything the first agent negotiated, can also be fatal to a commission claim. In Outerbridge trading as Century 21 Plateau Lifestyle Real Estate v Hall [2020] NSWCA 205, the court held that where an agent plays a significant causal role in a buyer purchasing a property, it may not be the effective cause of the sale. Being the effective cause of sale required more than a mere introduction of the eventual buyer, and the agent who effectively introduced the buyer must also play a role in the negotiations to conclude the sale. In that case, the agent that effected the sale played a crucial role in that it “resuscitated” the transaction after the buyer believed the initial engagement and negotiations through the first agent was at an end. Despite the work of the first agent in introducing the buyer to the property, the court decided it was the second agent that subsequently secured the sale that would otherwise not have occurred.
Form 6 Validity: The Commission Claim’s First Hurdle
Before the effective cause question even arises, the agent’s appointment must be valid. The POA states that a property agent is not permitted to act as an agent on behalf of a client in the absence of a valid appointment in the approved form. If an agent fails to complete a Form 6 correctly or it is incomplete, they may not be properly appointed to act, which could result in a loss of entitlement to commission.
The result of oversights on a Form 6 may seem minor on the face of it, but these oversights will have major impacts on an agent’s entitlement to commission. The Sunshine Group v Trappando litigation demonstrated this precisely: in that case, the Form 6 contained some discrepancies, the client terminated the contract and forfeited the deposit, and the agent sought to recover their commission. The court ultimately found in favour of the agent, but not without the agent paying significant legal costs that could have been avoided.
An agent can be the indisputable effective cause of a sale and still lose their commission if their Form 6 appointment is defective. These two requirements — valid appointment and effective causation — operate as separate thresholds, both of which must be cleared.
What This Means for Queensland Agents
The effective cause test operates differently depending on the type of appointment you hold. Under an exclusive or sole agency, your commission entitlement during the appointment period is considerably more secure — the question of who introduced the buyer is less relevant because you have exclusivity. The effective cause inquiry becomes acute when the exclusive period expires, when you operate under an open listing, or when a conjunction arrangement creates competing claims.
During any listing: document everything, and document it contemporaneously. Your attendance records, email exchanges with buyers, inspection logs, counter-offer correspondence, and any buyer follow-up communications are your evidence base if a dispute arises. Courts cannot credit conduct they cannot see. Entries in your CRM and emails sent from your agency address, in your capacity as the appointed agent, build the case file you may need later.
If a buyer you introduced signs with another agent: do not assume you have no claim, but do not assume you do either. The question is whether your work was still the operative cause of that buyer’s decision to purchase — or whether the second agent’s involvement was qualitatively different enough to constitute a fresh causal chain. Determining whether you are the effective cause of sale will always involve the terms of the agency agreement and the actual events of introduction, negotiations, offers, and acceptance.
If a second agent approaches your buyer: make sure your file demonstrates ongoing engagement. A gap in follow-up — weeks without contact — is the kind of factual vacuum that invites a court to find the second agent resuscitated a stalled transaction.
When operating on open listings alongside other agents: substitution of a buyer can easily lead to a dispute over whether the agent was the effective cause of sale, and care should be taken to carefully record and document the process. If the buyer pool is shared, your contemporaneous records of introduction, inspection, and negotiation are what distinguish your claim from a competitor’s.
For principals managing multi-agent teams or sub-agent networks: the Podium Project Marketing decision confirms that an agent need not have had direct contact with a buyer to be the effective cause of sale — but the organisational contribution must amount to a genuine causal link, not a passive administrative role. Document the structure of your sub-agent or referral arrangements and ensure all activity occurs under properly authorised Form 6 appointments.
The fundamental rule that the law applies here has been true for over a century, and it remains uncompromising: commission is earned by doing the thing that actually brought buyer and seller together. Showing up early, introducing the buyer, and then stepping back does not guarantee the prize. Staying in the transaction — actively facilitating, negotiating, and maintaining the relationship between buyer and seller — is what courts look for when they ask whether an agent’s efforts really brought about the sale.