How Do You Expose Vague Back-Charges in a Security of Payments Adjudication?

John Merlo
14 hours ago
12 min read

Key Takeaways

A timely but vague payment schedule may fail to properly articulate set-offs, which can limit the respondent's ability to rely on them during adjudication.
Under the Building Industry Fairness (Security of Payment) Act 2017 (BIF Act), respondents are typically barred from introducing new reasons for withholding payment in their adjudication response if those reasons were absent from the original schedule.
Carefully structuring your adjudication application to highlight jurisdictional flaws in the back-charges is likely to be more effective than introducing unprompted factual evidence.
The statutory 10-business-day decision timeframe runs from the "response date" and may be affected by the BIF Act's strict definition of "business days," particularly during the Christmas shutdown.

When a respondent's payment schedule lands on your desk hours before the deadline, and the $85,000 progress claim you submitted has been reduced to zero based on a single line item citing "defective site work," the frustration is immediate. They haven't provided defect notices, cost breakdowns, or photographic evidence—just a vague, unquantified back-charge designed to stall payment. For a Queensland licensed residential builder, the clock is now ticking to prepare an adjudication application under the Building Industry Fairness (Security of Payment) Act 2017.

The critical decision you face is where to aim your effort: at proving the work was perfect by flooding the adjudicator with site photos, or at dismantling the payment schedule's lack of jurisdictional detail to win on a procedural knockout. As this article explains, the sharpest strategy usually leans heavily towards the latter, while holding your factual evidence in reserve.

The Ticking Clock: Assessing the Payment Schedule for Jurisdictional Flaws

You have just received a payment schedule right on the deadline, but the amounts withheld are justified by vague, unquantified back-charges. Before the window to act closes, your immediate priority is classifying these set-offs so you can systematically dismantle them in your adjudication application. This section provides the procedural clarity needed to formulate a targeted counter-attack against deficient responses.

Separating BIF Act Procedural Bars from Contractual Set-Off Rights

While your building contract may theoretically allow a party to back-charge for defective work, the Building Industry Fairness (Security of Payment) Act 2017 imposes strict procedural rules on how those deductions must be detailed. This Act is the primary governing legislation that dictates the adjudication process and timeframes in Queensland. There is a distinct difference between possessing a contractual right to set-off—such as those commonly found in standard industry contracts provided by Master Builders Queensland—and satisfying the statutory requirement to articulate that deduction sufficiently within a payment schedule. For a builder in Queensland, this distinction is decisive.

If a respondent relies on a contractual right but fails to adequately state and substantiate the back-charge within the framework of the payment schedule, an adjudicator may reject the set-off. It should be noted that the Act requires the schedule to state the reasons for withholding payment, and whether a given reason is sufficient is a question of fact and degree for the adjudicator—so while a bare, unquantified back-charge is vulnerable, outcomes turn on the specific wording and circumstances.

Identifying Vague or Unquantified Defect Allegations

Consider a realistic scenario where you issue a progress claim, and the subcontractor's payment schedule arrives containing a single line item deducting $25,000 for "waterproofing defects." The document lacks photographic evidence, formal defect notices, and any breakdown of the calculation used to reach the withheld figure. This deficient schedule stands in stark contrast to a compliant response, which requires explicit cost calculations and clear references detailing how the alleged defects breach the contractual scope of work.

The Section 82 Bar on New Reasons in the Adjudication Response

Under Queensland law, the BIF Act strictly limits respondents from introducing new reasons for withholding payment in an adjudication response if those reasons were not detailed in their original payment schedule.

A strategic claimant can often lock the respondent into the four corners of their payment schedule, and the discipline required is to resist the temptation to overreach in the application itself.

In practice, the tactic is to quote the respondent's own withholding reason back to the adjudicator verbatim, then draw a line under it—characterising that line as the outer boundary of what the respondent is now permitted to argue. Where a schedule says only "defective site work" or "waterproofing defects" with a bare dollar figure, the claimant's submission should frame that language as the complete universe of the respondent's case, so that any defect notice, expert report, or cost breakdown appearing for the first time in the response is met with the objection that it is a new reason the respondent was obliged to raise, but did not. A common pattern seen in these disputes is the respondent who, realising the schedule is thin, attaches a lengthy statutory declaration or a fresh quantity surveyor's assessment to the response in an attempt to backfill the detail after the fact.

The claimant's leverage is to invite the adjudicator to disregard that material entirely rather than to argue its merits: engaging with the substance of a late-supplied breakdown risks conceding that the reason was validly raised in the first place. The sharper the claimant keeps the distinction between "reasons stated in the schedule" and "evidence supplied only in the response," the harder it becomes for the respondent to argue they have merely elaborated on an existing reason rather than introduced a prohibited new one.

Structuring Your Adjudication Application Under Section 79

With the flawed payment schedule analysed, the focus shifts to drafting your adjudication application and lodging it with the registry. At this stage, your submissions must be structured precisely to highlight the respondent's jurisdictional failures without overcomplicating your own security of payment claim. Preparing a focused, procedurally sound application is your strongest leverage point in securing the withheld funds.

Initiating a Security of Payments Application for Unpaid Amounts

Under the BIF Act, a Queensland claimant is legally entitled to apply for adjudication when the respondent fails to pay the owed amount in full by the due date. When the scheduled amount falls short due to baseless setoffs, section 79 of the BIF Act allows a claimant to apply to the registrar for adjudication of a payment claim. Where the respondent has given a payment schedule for a lower amount, the application must generally be made within 20 business days after the due date for the progress payment, so the window to act is short. To effectively initiate the process, you must identify the payment claim and the payment schedule to which the application relates, tying your submissions back to the scope of the original payment claim so the adjudicator can trace the exact work being claimed.

The application is lodged with the Adjudication Registry administered by the QBCC. Critically, under section 79(4) you must also give the respondent a copy of the application (and any accompanying submissions) within 4 business days of making it—a service step that is easy to overlook and can imperil an otherwise sound application.

Highlighting the Respondent's Jurisdictional Failures

To effectively attack vague back-charges, structure your written submissions to systematically dismantle the respondent's scheduling deficiencies:

Identify the complete absence of mathematical calculations linking the withheld dollar amount to the alleged scope of the defective site work.
Highlight any missing contractual notices, such as formal directions to rectify, that should have been issued prior to the payment schedule.
Point out the respondent's failure to substantiate the alleged defects with photographic or independent expert evidence within the schedule itself.
Argue that these omissions represent a fundamental failure to articulate reasons, rendering the deductions procedurally invalid for the purpose of the adjudication.

Managing Subcontractor Indemnity and Set-Off Clauses

Warning: Respondents frequently attempt to rely on broad subcontract indemnity clauses—such as those commonly found in standard residential subcontracts provided by the Housing Industry Association—to justify withholding funds en masse. The intended function of these clauses is to transfer risk back to the subcontractor, but this clause is only enforceable in an adjudication if the respondent has strictly complied with the BIF Act's scheduling requirements. These provisions do not operate as an unassailable shield; their effectiveness is strictly conditional upon the respondent adequately quantifying the set-off in their payment schedule. If a respondent attempts to bypass statutory procedures by citing a general indemnity without quantification, the deduction is at real risk of being rejected, making it prudent for claimants to obtain targeted construction law advice when drafting their application.

The Evidentiary Trap: Why You Shouldn't Submit New Factual Arguments

Your instinct may be to attach hundreds of emails and site photos proving the alleged defects are entirely fabricated. However, over-answering is a dangerous trap that can distract the adjudicator and introduce fatal complexities to a clean procedural win. This section curbs that instinct to over-explain, providing the discipline needed to protect a strong procedural position.

The Danger of Introducing Prohibited New Evidence

In Queensland adjudication proceedings, claimants should primarily focus their application on dismantling the respondent's payment schedule rather than introducing entirely new factual evidence outside the original claim.

An adjudication application is generally not the proper forum to introduce entirely new factual claims about the project that were absent from the original payment claim. In a standard subcontractor dispute, attempting to pre-emptively litigate a building defect claim by flooding the application with site diaries often shifts the focus away from the respondent's procedural failures. By concentrating the attack on invalidating the respondent's schedule instead of reinventing the original claim, a claimant keeps the spotlight squarely on what the respondent failed to substantiate.

Keeping the Focus on the Respondent's Lack of Substantiation

A laser-focused jurisdictional challenge can often be significantly more persuasive to an adjudicator than a sprawling, "kitchen sink" application. Adjudicators are working to a compressed statutory timetable and are reading these applications under real time pressure; an application that opens with a tight, two-page argument on why the schedule fails to articulate its reasons is far easier for a decision-maker to adopt than one that buries the same argument behind a hundred pages of site diaries, photographs, and email chains. Some claimants, confident their build is sound, lead with the quality of the work rather than the deficiency of the schedule—inadvertently reframing the dispute as a factual contest about defects, which is precisely the contest the respondent wants and the one the vague schedule was never entitled to trigger.

Forcing the adjudicator to wade through irrelevant photographs can also carry a subtler cost: once the decision-maker has engaged with the substance of the alleged defects, it becomes psychologically harder for them to then rule that those defects were never properly raised, because the material has already been treated as live. There is also a practical drafting risk that voluminous annexures introduce inconsistencies or admissions that a well-advised respondent will exploit. The stronger position is usually to hold the factual material in reserve, reference it only to the extent needed to show the claimed work was performed and let the respondent's own thin schedule do the work of losing the point for them.

Adjudication Outcomes, Deadlines, and Fee Reapportionment Strategies

Once the application is lodged, the timeline tightens immediately. You need to know exactly when to expect the decision and how to position your claim to ensure the respondent pays the adjudicator's costs for relying on baseless, unquantified back-charges. This section details the statutory timelines governing the process and explores strategies for shifting the financial burden of the dispute back onto the opposing party.

The Strict 10-Business-Day Decision Window

Queensland adjudicators are statutorily required to issue a decision within 10 business days from the response date for standard payment claims.

Under section 85 of the BIF Act, this statutory deadline is binding on the adjudicator to facilitate the rapid resolution of payment disputes. It is worth noting, however, that section 85 operates subject to section 86, which allows the parties to agree to extend the time for the decision—so while the default window is tight, it is not entirely immovable. Understanding these precise timeframes is crucial for enforcing your payment rights under the BIF Act and forecasting exactly when the withheld funds might be released back into your business.

Navigating the Christmas Shutdown Trap

Warning: Because these deadlines drive your cash-flow forecasting, the timing of the holiday period deserves close attention. The strict 10-business-day timeline halts entirely if the adjudication period falls within the statutory holiday shutdown. The Christmas shutdown BIF Act provisions explicitly exclude the dates from December 22 to January 10 from the definition of "business days." This pauses the clock, meaning builders must account for this statutory delay when managing project cash flow over the new year.

Pushing for 100% Fee Apportionment Against the Respondent

Claimants can actively request that the adjudicator apportion 100% of the adjudication fees against the respondent if the payment schedule relied on frivolous or entirely unsubstantiated back-charges.

Section 95 of the BIF Act provides that the claimant and respondent are jointly and severally liable to pay the adjudicator's fees and expenses. The adjudicator has a discretion as to apportionment, and highlighting the respondent's lack of jurisdictional detail may persuade them to shift more—or in a clear case all—of the cost burden onto the opposing party. This outcome is discretionary rather than guaranteed and turns on the adjudicator's view of the conduct. This cost-shifting strategy is a vital tool in commercial dispute resolution, particularly when defending against severe cash flow disruptions that can trigger the insolvency risks outlined in the Corporations Act 2001, which governs company viability when standard progress payments are heavily reduced by unquantified deductions.

Supreme Court Judicial Review Limits

While an adjudicator's decision is typically enforceable as a judgment debt, a respondent may attempt to challenge it by seeking a judicial review in the Supreme Court for jurisdictional error.

Because a respondent can pursue this challenge, submitting a technically perfect application is critical to protecting the finality of the adjudicator's decision. If the initial procedural dispute transforms into a broader, factual battle over the actual existence of defective work, those substantive arguments are often better suited for the Queensland Civil and Administrative Tribunal, which serves as the forum for broader building defect disputes that frequently overlap with BIF Act payment issues. Furthermore, if a Supreme Court challenge arises, builders will likely need to engage legal professionals regulated by the Queensland Law Society, the professional body governing solicitors who advise on complex jurisdictional challenges in Queensland.

Conclusion

When that $85,000 progress claim is suddenly reduced to zero by a vaguely worded "defective site work" back-charge, the instinct is almost always to flood the respondent with evidence proving the quality of your build. However, as a Queensland residential builder navigating the BIF Act, you now know that winning an adjudication does not necessarily require proving your work was flawless. Instead, it often requires proving that the respondent's payment schedule was procedurally flawed.

By separating the respondent's theoretical contractual rights from their strict statutory obligations, you can expose the lack of quantification and detail in their deductions. Focusing your adjudication application on these jurisdictional failures—rather than introducing voluminous new site photos or daily logs—is highly likely to yield a cleaner, faster outcome while locking the respondent out of raising new reasons for non-payment.

Before you begin assembling a massive dossier of factual evidence to disprove a poorly drafted payment schedule, review the document for quantification gaps and missing contractual notices. Mapping out every missing calculation and absent defect notice forms the foundation of a targeted jurisdictional challenge.

The stakes of getting this wrong are real: a flawed application can hand the respondent grounds for judicial review, and a heavily reduced progress payment can place genuine strain on your cash flow. Because the adjudication window is measured in days rather than weeks, the time to have your application reviewed is now. If you have received a payment schedule built on vague, unquantified back-charges, contact Merlo Law to have your position assessed by a construction lawyer before you lodge.

FAQS

What happens if a payment schedule contains back-charges without cost breakdowns?

In Queensland, the BIF Act requires a payment schedule to state the respondent's reasons for withholding payment. Where a back-charge is asserted with a bare dollar figure and no supporting detail, an adjudicator may find the reason inadequately articulated and decline to allow the deduction. The sufficiency of a stated reason is assessed case by case, so a vague, unquantified back-charge is at real risk of being rejected, though the outcome depends on the specific wording and circumstances.

Can a respondent add new defect allegations in their adjudication response?

Under section 82 of the BIF Act, a respondent is typically barred from introducing new reasons for withholding payment in their adjudication response if those reasons were not included in the original payment schedule. This strict procedural limitation often prevents parties from retroactively substantiating vague defect claims during the adjudication phase.

How long does an adjudicator have to make a decision in Queensland?

For standard payment claims, Queensland adjudicators are statutorily required under section 85 of the BIF Act to issue a decision within 10 business days from the response date. This strict timeframe facilitates rapid dispute resolution, though it pauses entirely during the BIF Act's statutory Christmas shutdown period.

Who pays the adjudicator's fees in a BIF Act dispute?

Section 95 of the BIF Act provides that the claimant and respondent are initially jointly and severally liable to pay the adjudicator's fees and expenses. However, adjudicators possess the discretion to apportion 100% of these fees against a respondent if they determine the payment schedule reasons were frivolous or completely unsubstantiated.

Should I include all my site photos in my adjudication application to disprove the back-charges?

Claimants should generally focus their BIF Act adjudication application on dismantling the respondent's deficient payment schedule rather than introducing an overwhelming volume of new factual evidence. Flooding the application with site photos can distract from a strong procedural argument and may unnecessarily complicate the adjudicator's assessment.

Does a general subcontract indemnity clause validate a set-off in a payment schedule?

While subcontract indemnity clauses are designed to transfer risk, their enforceability in an adjudication context depends heavily on the respondent adhering to BIF Act procedural requirements. Citing a broad indemnity clause without quantifying the specific financial deduction in the payment schedule is at real risk of resulting in the back-charge being rejected by the adjudicator.

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