How Do You Secure Payment for a Handshake Variation Under the BIF Act?

Key Takeaways

• Send a written variation notice within 24 hours: Verbal site instructions rarely survive adjudication under the Building Industry Fairness (Security of Payment) Act 2017 (BIF Act), so paper the change before the next progress claim lands.

• Get it in writing before work starts: The Queensland Building and Construction Commission Act 1991 (QBCC Act) generally requires variations to be documented in writing before commencement — non-compliance can attract penalties of up to 20 penalty units for domestic building contract variations under Schedule 1B section 40, and up to 80 penalty units for building contracts (including commercial contracts) under section 67G.

• Cross-check every renegotiated payment clause: Extended payment terms and "pay when paid" clauses are statutorily void in Queensland, so a poorly drafted deed of variation can strip away the very concession you negotiated. Under section 67W of the QBCC Act, any provision in a commercial building contract requiring payment later than 15 business days after submission of a payment claim is void. Under section 67U, the equivalent cap for construction management trade contracts and subcontracts is 25 business days. The applicable threshold depends on where your contract sits in the contractual chain — confirm which cap applies before signing any renegotiated deed.

• Protect your adjudication rights at signing: Any clause asking you to waive your BIF Act rights in exchange for variation approval is unenforceable — but only if your underlying variation paperwork establishes a clean contractual entitlement to begin with.

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The concrete trucks are banking up on the street, the site supervisor is pacing, and the principal has just pointed to an unmapped utility line, telling you to "just deal with it and add it to the next claim." To keep the pour moving, you shake on the variation and instruct your team to commence the extra work. In that moment, you have traded real money for a verbal promise — and Queensland construction law makes that promise nearly impossible to enforce. If the principal's memory conveniently fades when the invoice lands 30 days later, your company is exposed to carrying the cost of that delay and the extra materials. This article walks you through exactly what those 24 hours should look like, the written-form rules that govern your variation under the QBCC Act, the renegotiation traps that quietly void your payment terms, and how to keep your adjudication rights intact under the BIF Act when the principal reneges.

Assessing the Handshake Agreement and the 24-Hour Documentation Window

The principal has just verbally directed an expensive scope change on site to avoid delays, and you are weighing whether to pull the trigger on the work immediately. The immediate procedural priority is formalising that verbal instruction into a binding document before the machinery moves, ensuring the additional cost survives the scrutiny of the next payment cycle.

First, Identify Which Contract You Are Dealing With — and Which Act Applies

Before applying anything in this article, identify which type of contract you hold, because the two Acts do not apply uniformly across all construction work. Broadly, there are three categories: a domestic building contract (between a builder and a homeowner), a commercial or head building contract (at the top of the contractual chain), and a construction management trade contract or subcontract (further down the chain). The reach of each Act differs depending on which of these you are in.

The QBCC Act regulates these contracts through different provisions: Schedule 1B governs domestic building contracts and is consumer-protection focused, while Part 4A governs building contracts other than domestic building contracts, together with subcontracts and construction management trade contracts. The QBCC Act also does not regulate every construction contract — its rules apply to "building work" as defined under that Act, which is narrower than the broad "construction work" concept used in the BIF Act. Critically, the BIF Act's security of payment regime does not typically apply to most domestic building contracts. Where a construction contract is for domestic building work and a resident owner is a party who lives in, or intends to live in, the building, the BIF Act's payment claim and adjudication pathway is generally unavailable against that home owner.

The BIF Act does still apply between a head contractor and its subcontractors on a residential project, so a builder cannot adjudicate against the resident home owner but must still meet its own payment obligations to subcontractors. The practical upshot is that much of the rapid-recovery analysis in this article assumes a commercial building contract or a subcontract — where BIF Act adjudication is available — rather than a contract with a resident home owner. Where this article discusses domestic building contracts and Schedule 1B section 40, it does so to address the QBCC Act's written-form rules, not to suggest that the BIF Act adjudication pathway is available against a resident owner.

Differentiating Contractual Scope Changes from Statutory Payment Rights under the BIF Act

Many contractors assume that simply performing the requested work entitles them to force payment through the adjudication system. It does not. Creating an entitlement and recovering payment are two different legal questions: the QBCC Act and your contract govern the first, while the BIF Act governs the second. The BIF Act provides a rapid pathway to enforce payment, but it does not invent an entitlement out of thin air. An adjudicator must look to the underlying contract to decide whether the variation is valid in the first place.

While the BIF Act provides the rapid recovery mechanism where it applies — that is, on commercial building contracts and subcontracts, and as to contracts between a builder and subcontractors, but generally not on contracts with a resident home owner — a valid written variation under the QBCC Act is often required to establish the underlying legal entitlement that an adjudicator will look to in Queensland.

If the underlying contract explicitly requires variations to be approved in writing—and almost all standard form commercial and domestic contracts do—a verbal instruction may fail to satisfy the contractual prerequisites. Proceeding without written confirmation can sever your legal right to claim the additional amount.

Why Site Instructions Fail at the Adjudication Stage Without Formal Written Variations

Expert insight: The pattern we see repeatedly is a subcontractor who has a strong working relationship with a project manager, takes a verbal instruction over the phone or at a toolbox meeting, and prices the variation honestly into the next progress claim assuming the rapport will carry the day. The relationship then changes — the project manager leaves, the head contractor's cash position tightens, or a defects dispute emerges — and suddenly every variation that was waved through verbally is being challenged line by line in the payment schedule.

When that claim then proceeds to adjudication, the adjudicator's reasons frequently turn on a single point: whether the claimant has proved a contractual right to be paid for the varied work. Email trails saying "thanks mate, will sort the paperwork later" rarely clear that bar where the contract contains a strict written-variation clause, and the adjudicator may decide there is no contractual basis to value the work at all — even where the work was clearly performed and clearly benefited the respondent. The tactical lesson is that the time to paper a variation is when the relationship is good, not when it has already broken down, because by the time you need the document for adjudication, the other side has no incentive to sign anything.

 

The 24-Hour Checklist: Formalising a Site Variation Before the Next Claim

To convert a high-risk handshake into a legally enforceable variation before the end of the payment cycle, you need to lock down the documentation immediately. Work through the following steps within 24 hours to secure your position and avoid a future variation dispute:

• Send a formal written notice: Email the principal or superintendent confirming the exact verbal instruction given on site, including the date, time, and the person who gave it.

• Document the price and scope: Clearly detail the precise scope of the additional work and the agreed price, or state the method by which the price will be calculated (e.g., standard schedule of rates).

• Request explicit written sign-off: State directly in the correspondence that work will not commence until the attached variation document is signed and returned.

• Pause affected work if necessary: If the contract allows, and the principal stalls on providing written approval, halt the specific work affected by the variation rather than proceeding at your own financial risk.

 

Navigating the QBCC Act's Strict Written Form Requirements for Contract Variations

The immediate site emergency is managed, but you now face strict regulatory obligations that dictate exactly when and how the variation must be signed off. Failing to align your paperwork with the specific section governing your project type doesn't just threaten your payment—it exposes the company to direct intervention from the regulator via a statutory liability pathway.

Schedule 1B Section 40 vs Section 67G Thresholds for Domestic and Commercial Projects

The statutory rules for documenting QBCC Act variations differ fundamentally depending on whether you are executing a regulated domestic building contract or a commercial building contract. For residential projects, the primary legislation governing builder conduct in Queensland, the Queensland Building and Construction Commission Act 1991 (Qld), imposes rigid pre-commencement rules to protect consumers.

Under Schedule 1B, Section 40 of the QBCC Act, domestic building contract variations attract two distinct and separately enforceable obligations.

The first obligation, under section 40(2), requires the building contractor to give the building owner a copy of the variation in writing before the earlier of two events: 5 business days elapsing from the day the contractor and owner agree to the variation, or the varied work commencing. A maximum penalty of 20 penalty units applies for non-compliance with this requirement.

The second obligation, under section 40(5), is stricter and operates independently: the building contractor must not start to carry out any domestic building work the subject of the variation before the building owner agrees to the variation in writing. This is not satisfied merely by delivering a written copy of the variation document — it requires the owner's actual written agreement before a single tool is lifted on the varied scope. Non-compliance with section 40(5) is a separate demerit point offence.

In practical terms, a contractor who hands over the written variation document on the day of agreement but commences work the following morning — before receiving the owner's countersignature — has complied with section 40(2) and simultaneously breached section 40(5). Both obligations must be satisfied. For commercial contracts, written form requirements are governed separately under the Act, shifting the focus from consumer protection to strict commercial record-keeping.

The 80-Penalty Unit Exposure for Failing to Put Commercial Variations in Writing

Under Section 67G of the QBCC Act, building contracts where the reasonable cost of the work exceeds $10,000 — which captures most commercial projects — must be reduced to writing before the building work commences, and must include all seven elements of prescribed formal content set out in section 67G(4):

A.     the scope of the building work;

B.     the date by which the building work is to be completed;

C.    the amount to be paid, or how that amount is to be calculated;

D.     the parties' agreement about retention amounts and securities to be held;

E.      the name of the building contractor who is the contracted party;

F.      that contractor's licence number as it appears on their licence; and

G.    the address of the land where the building work is to be carried out. Where a variation pushes a sub-$10,000 contract over the threshold, the contract incorporating that variation must also be reduced to writing before further work is carried out. Failing to meet these requirements is an offence, with the statutory framework attaching a maximum exposure of up to 80 penalty units for non-compliance.

Directors who keep operating on handshakes do not just risk individual payment disputes — they risk the regulator's attention. Persistent failure to properly document commercial contracts and variations can attract disciplinary action and accumulate demerit points, and in serious cases may end with the QBCC disqualifying the contractor from holding a licence — a person who accumulates 30 demerit points within any three-year period faces a three-year disqualification, and a second such accumulation within ten years results in a lifetime bar.

Can You Rely on the "Urgent Work" Exception Under Schedule 1B Section 40?

Relying on the statutory exception for urgent work to bypass written requirements is a highly conditional defence that often fails in formal disputes unless the situation involves a genuine, immediate hazard. Both Schedule 1B section 40(4) (for domestic variations) and section 67G(6) (for building contracts generally) contain narrow urgent work carve-outs, but each requires the contractor to prove not only that the work was urgent, but also that it was not reasonably practicable to produce a written document in the particular circumstances. The Queensland Building and Construction Commission, which enforces these compliance standards, generally expects builders to exhaust practical avenues to document a change before citing urgency as a legal justification.

Example: During a residential renovation in Brisbane, your framing crew uncovers extensive, previously hidden structural rot in the load-bearing walls that threatens to collapse the roof structure within hours. In this specific scenario, executing immediate make-safe shoring work without waiting for the homeowner to sign a formal variation document might satisfy the urgent work exception, as the delay could cause severe property damage. However, if you attempt to rely on this same urgency excuse simply because a delayed materials delivery required you to swap out flooring types to keep the schedule moving, a tribunal is likely to reject the defence and may invalidate the associated claim. Bear in mind that on a domestic building contract with a resident home owner, the BIF Act adjudication pathway is generally not available in any event, so the recovery dispute here is governed by the contract and the QBCC Act rather than by BIF Act adjudication; the rapid adjudication analysis in this article is directed at commercial building contracts and subcontracts.

The Dangers of Accidentally Introducing Void Payment Terms During a Renegotiation

When the principal finally agrees to draft the formal variation, they may seize the opportunity to quietly alter the project's overall payment terms in their favour. Signing a renegotiated contract that accepts delayed payment structures or downstream risk transfer can inadvertently trigger a statutory liability pathway, voiding your contractual protections entirely under Queensland law.

How Extending Head Contract Terms Beyond 15 Business Days Triggers Section 67W

Before examining the subcontract position, head contractors and principals must be aware of a separate and stricter statutory cap that operates one tier up the contractual chain. Under section 67W of the QBCC Act, any provision in a commercial building contract that provides for payment of a progress payment later than 15 business days after submission of a payment claim is void. This 15 business day cap applies between a principal and a head contractor — that is, at the top of the payment chain — and is entirely separate from the 25 business day cap that governs subcontracts under section 67U.

The practical consequence is significant: a head contractor who accepts renegotiated payment terms of, say, 20 business days in exchange for a variation concession has accepted a term that is already statutorily void. The head contractor remains entitled to payment within 15 business days regardless of what the renegotiated deed says, and the principal obtains no benefit from the extended term whatsoever. When reviewing any renegotiated payment clause, confirm at the outset whether the contract is a commercial building contract (15 business days, section 67W) or a construction management trade contract or subcontract (25 business days, section 67U), because the applicable cap differs and conflating the two is a recurring source of error.

How Extending Subcontract Terms Beyond 25 Business Days Triggers Section 67U

When formalising a variation dispute via a renegotiated contract, builders must remain vigilant regarding the strict statutory caps placed on payment timeframes. Under Queensland law, a provision in a construction management trade contract or subcontract providing for payment of a progress payment later than 25 business days after submission of a payment claim is void.

Any renegotiated subcontract provision attempting to delay progress payments beyond 25 business days is automatically rendered void under Section 67U of the QBCC Act.

This means that if a principal attempts to trade a higher variation sum for an extended 45-day payment cycle, that newly drafted payment term is legally ineffective from the moment it is signed. Consider the practical consequence: a head contractor agrees to a $180,000 variation sum on the condition the subcontractor accepts 45-day payment terms instead of the standard 25 business days. The variation sum stands. The 45-day clause does not. The subcontractor can serve a payment claim on the statutory cycle and demand payment well before the head contractor expected to fund it — keeping every dollar of the negotiated variation uplift.

The Absolute Prohibition on "Pay When Paid" Clauses Under Section 74 of the BIF Act

Warning: A "pay when paid" clause has no legal effect in Queensland — full stop. A principal might argue that approving an expensive variation forces them to pass the financial risk upstream, so they can only pay you after the developer pays them. Section 74 of the BIF Act shuts that argument down. Any provision that makes your payment contingent on, or its due date dependent on, a third party paying the principal has no effect under the legislation and offers the principal no protection at all. Directors facing pressure to accept these conditional terms should obtain independent construction law advice before signing the deed.

The Hidden Trap: When Renegotiated Terms Quietly Default to the Statutory Position

Expert insight: The trap we see most often is a head contractor who agrees, in the heat of a variation negotiation, to push their subcontractor's payment cycle out from 25 to 35 or 45 days in exchange for absorbing a higher variation sum or accepting a liquidated damages concession. The commercial logic feels balanced at the table — the subcontractor gets paid more, the head contractor gets longer to fund the claim — but the moment that extended payment term is signed, it can be statutorily ineffective, and the subcontractor's payment timeframe reverts to the default position prescribed by the legislation.

The practical consequence is that the head contractor has given away the variation concession in exchange for a payment-term benefit that does not legally exist, and the subcontractor can serve a payment claim and demand payment on the default statutory cycle while still holding the higher variation amount. We also see the inverse problem: builders who genuinely intended to comply but who copy-pasted payment clauses from interstate template contracts (particularly New South Wales precedents drafted under different timing rules) and only discover during a payment dispute that the clause does not survive Queensland statutory scrutiny. Before signing any renegotiated deed of variation, the payment timing clauses should be cross-checked against the specific statutory caps for the contract type — head contract, subcontract, or construction management trade contract — because the consequences of getting it wrong are not negotiable between the parties.

Failing to recognise when a renegotiated term is legally ineffective can compromise your ability to accurately calculate the BIF Act payment schedule deadline for your next claim.

Preserving Your BIF Act Adjudication Rights When the Principal Reneges on Price

Even after you secure a perfectly drafted written variation, a hostile principal may still refuse to pay it on the next cycle, citing set-offs or phantom defects. Your documentation strategy must anticipate this exact moment, ensuring the paperwork smoothly facilitates a rapid adjudication response without providing the respondent any procedural loopholes.

Why You Cannot Trade Away Your BIF Act Rights — Even for a Bigger Variation

During intense renegotiations, a principal may demand that in exchange for approving a lucrative variation, you agree to waive your right to pursue future adjudication or submit further claims under the Building Industry Fairness (Security of Payment) Act 2017 (Qld). This attempt to contract out of the legislation is directly prohibited by section 200 of the BIF Act, which prevents parties from excluding, limiting or contracting out of any of the Act's provisions.

Under section 200 of the BIF Act (titled "Contracting out prohibited"), any clause inserted during a renegotiation attempting to waive a contractor's right to rapid adjudication is void and unenforceable in Queensland. Section 200 provides that the provisions of the Act have effect despite any contrary contractual provision, and that any term which is contrary to the Act, purports to exclude or limit its operation, or may reasonably be construed as an attempt to deter a person from taking action under the Act, is of no effect.

Even if a director signs a variation document containing a waiver clause, the statutory right to enforce payment via adjudication remains intact. If a principal is asking you to waive adjudication rights right now in exchange for variation approval, that is the moment to have the deed reviewed — not after you have signed it. A short call with a Queensland construction lawyer at this stage typically costs a fraction of recovering the variation through litigation later.

Structuring the Variation Document to Serve as a Valid Foundation for the Next Payment Claim

To ensure that your formalised variation serves as an unimpeachable foundation for progress payment claims Queensland, the documentation must bridge the gap between basic QBCC Act compliance and the stringent requirements of the BIF Act. A legally robust variation document should clearly reference the underlying contract clause that authorises the change in scope.

It must itemise the pricing methodology, clearly delineate the additional work from the original scope, and carry the authorised signature of the principal or superintendent. A structurally sound variation document removes ambiguity from the outset. If the dispute escalates, your construction lawyer will have far less ground to defend, and the respondent will have far fewer procedural angles to exploit.

What If the Unwritten Work Has Already Been Performed?

Many directors arrive at this issue after the fact, with weeks or months of unwritten variation work already on the books and the next progress claim looming. The position is not hopeless, but it does require a different strategy.

The first step is a written variation register: a single document, sent to the principal or superintendent, that retrospectively itemises every site instruction, the date it was given, the person who gave it, the scope performed, and the price. Even if the principal refuses to counter-sign, the document creates a contemporaneous record that is significantly stronger than reconstructing events months later in an adjudication response.

The second step is a careful review of the underlying contract for any clauses that allow ratification of verbal instructions, or that operate as a deemed acceptance where the principal fails to respond to written notice within a set period. Some standard-form contracts contain mechanisms that can rescue a partly documented variation — but only if the notice is served correctly and on time.

The third step is realistic triage. Variations under a few thousand dollars may not justify the cost of a contested adjudication, while six-figure unwritten variations almost always warrant immediate legal review before the next payment claim is served. Getting that triage right is usually where a construction lawyer adds the most value.

Conclusion

When the concrete trucks are banking up and the principal points to an unmapped utility line, the pressure to "just deal with it" on a handshake is immense. However, as Queensland building company directors frequently discover, executing that verbal instruction without securing the requisite paperwork within 24 hours can cripple the company's ability to recover those costs. We have seen how failing to reduce commercial variations to writing under section 67G of the QBCC Act can expose a builder to severe regulatory penalties, and how attempting to recover unwritten variations through the BIF Act adjudication pathway often results in the claim being rejected for lack of jurisdiction.

Furthermore, we have examined the severe risks associated with poorly executed renegotiations. Accepting extended payment cycles or "pay when paid" clauses during a variation dispute can render those provisions statutorily void, potentially forcing the contractor to rely on default legislative terms that misalign with their cash flow. Even when the principal demands a waiver of security of payment rights in exchange for approving a variation, section 200 of the BIF Act — which expressly prohibits contracting out of the Act — operates to preserve the contractor's enforcement pathways.

The commercial reality is that securing your right to payment requires more than performing the work to a high standard; it demands rigorous administrative discipline at the moment the instruction is given. If your company has performed more than $20,000 of unwritten variation work in the last quarter, if you are being asked to sign a deed of variation this month, or if a principal has just hinted at trading a variation approval for extended payment terms or a waiver clause — those are the trigger moments to pick up the phone before the next progress claim goes out. Contact our construction law team for a focused review of your variation paperwork, your renegotiated payment clauses, and the enforceability of your upcoming BIF Act claim.

 

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FAQs

Can I claim payment for a variation if it was only agreed to verbally on site?

Claiming payment for a purely verbal variation is highly risky and often fails during formal dispute resolution. Note first that the BIF Act's adjudication pathway is generally not available on a domestic building contract where a resident owner is a party — that exclusion means a builder usually cannot adjudicate against an owner-occupier homeowner and must instead pursue the contract or the QBCC Act. Where the BIF Act does apply, such as on a commercial building contract or a subcontract, it provides a payment recovery mechanism, but the adjudicator will still generally look to the underlying contract and the QBCC Act, which typically require variations to be documented in writing. Without written proof, you may struggle to establish the legal entitlement required to enforce the claim.

What happens if I don't put a commercial contract variation in writing?

Failing to reduce a building contract — including most commercial contracts where the reasonable cost of the work exceeds $10,000 — to writing is an offence under section 67G of the QBCC Act, and the same applies where a variation takes a smaller contract over that threshold. This breach can expose the building company to regulatory action, including a maximum penalty of up to 80 penalty units. Furthermore, the lack of written documentation significantly complicates any subsequent effort to recover the variation costs via adjudication.

Does the 'urgent work' exception mean I don't need written variations for emergency repairs?

The 'urgent work' exception under Schedule 1B Section 40 is narrow and highly conditional, typically requiring a genuine emergency, such as a risk of structural collapse or severe property damage. It cannot be relied upon simply because there are site delays or commercial pressures to keep the project moving. If an adjudicator determines the work was not genuinely urgent, the lack of a written variation may invalidate your claim.

Can a principal legally insert a 'pay when paid' clause into a renegotiated contract?

No, a principal cannot legally enforce a "pay when paid" clause in Queensland. Section 74 of the BIF Act expressly states that a "pay when paid" provision in a construction contract has no effect. Any attempt to insert such a clause during a contract renegotiation is statutorily void.

What is the maximum payment term I can agree to in a subcontract variation?

Under section 67U of the QBCC Act, any provision in a construction management trade contract or subcontract providing for a progress payment later than 25 business days after submission of a payment claim is void. If a renegotiated variation attempts to extend subcontract payment terms beyond this strict statutory limit, the extended term is legally ineffective.

Can I agree to waive my BIF Act adjudication rights to secure a profitable variation?

No, you cannot legally contract out of the BIF Act. Section 200 of the Act (titled "Contracting out prohibited") ensures that any clause attempting to waive your right to pursue future adjudication or submit progress claims is void and unenforceable. This applies whether the waiver is express or whether the clause may simply be construed as an attempt to deter action under the Act. Your statutory right to enforce payment remains protected regardless of what the renegotiated document states.

What documentation should I keep in a site variation register?

A robust variation register should record, for every change: the date and time the instruction was given, the name and role of the person who gave it, the precise scope of additional work, the agreed price or pricing method, the underlying contract clause that authorises the variation, and the signature of the principal or superintendent. Maintaining this register contemporaneously — rather than reconstructing it later — is one of the strongest defences against line-by-line challenges in a payment schedule.

How quickly can I challenge a short payment through BIF Act adjudication?

The BIF Act sets strict statutory timeframes for serving payment claims, receiving payment schedules, and applying for adjudication. Missing any of these deadlines by even a single business day typically extinguishes your right to adjudicate that claim, so the timing of your paperwork is just as important as its content. A construction lawyer can map the specific deadlines that apply to your contract type before you serve the claim.

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This guide is for informational purposes only and does not constitute legal advice. For advice tailored to your specific circumstances, please contact Merlo Law

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