Security of Payments: Can You Expand a Vague Payment Schedule in a BIF Act Adjudication Response?

Q: Can I add new reasons for withholding payment in my adjudication response?

No, section 82(4) of the BIF Act explicitly prohibits a respondent from raising any reasons for withholding payment in an adjudication response that were not provided in the original payment schedule. Any attempt to introduce new substantive reasons at the response stage is likely to be disregarded by the adjudicator.

John Merlo
8 hours ago
12 min read

Key Takeaways

Serving a payment schedule beyond the statutory limit of 15 business days may expose your business to liability for the full amount claimed, regardless of contractual assessment periods.
Under section 82(4) of the Building Industry Fairness (Security of Payment) Act 2017 (BIF Act), you are strictly prohibited from introducing new substantive reasons for withholding payment in an adjudication response if they were not explicitly detailed in your payment schedule.
Generic schedule descriptions like "defective work" are often insufficient to allow the introduction of detailed expert defect reports at the adjudication stage.
While a missed deadline creates statutory "pay now, argue later" liability, head contractors may still pursue recovery of overpayments in final civil proceedings or later contractual payment cycles.

Your project manager has just handed you a newly served adjudication application from a disgruntled subcontractor. Flipping to your company’s payment schedule, you look for the detailed breakdown of the back-charges, delays, and incomplete works that justify the $200,000 deduction you instructed them to make. Instead, you find a single, one-line entry: "defective work."

You know the defects are real. You have emails, site photos, and you are ready to commission a 50-page expert defect report to attach to your adjudication response. The immediate question is whether an adjudicator will accept that expert evidence to flesh out a vague schedule, or whether those reports will be struck out entirely as barred "new reasons" under Queensland’s security of payment laws. When the clock is ticking on an adjudication response, you need to know exactly what can be salvaged, what is legally barred, and whether your business is about to pay for a subcontractor's mistakes because of an administrative shortcut.

The 15-Business-Day Decision Window: When Standard Contracts Mask BIF Act Reality

You have just received an adjudication application from a subcontractor, and a quick check of the dates reveals your contract administrator relied on a 21-day contractual timeframe to issue the payment schedule, missing the statutory deadline. At this stage, you need to understand the immediate liability exposure and whether any assessment rights remain before deciding whether to settle or fight.

Why the 15-Day Statutory Limit Overrides Your Contract

Head contractors have a hard maximum of 15 business days to issue a payment schedule Queensland. The BIF Act outlines the strict section 76 timeframes governing mandatory response periods for head contractors across the state.

Under Queensland law, head contractors must serve a payment schedule within the timeframe specified by the contract, or a maximum of 15 business days after receiving the claim, whichever is earlier. If the contract is silent on the timing for a payment schedule, the 15-business-day rule operates as the default limit.

Why Contractual Assessment Periods Offer No Protection

Warning: Standard-form contractual assessment periods of 21 or 28 days are ineffective to extend your deadline to the extent they exceed the 15-business-day maximum mandated by the BIF Act. Because section 76 requires you to comply with whichever period ends first, a longer contractual review period simply cannot push the statutory deadline out—and the anti-avoidance provision in section 200 of the BIF Act prevents parties from contracting out of the Act's requirements. Relying on a 21-day contractual review period can expose your business to significant payment liabilities, because the statutory cap overrides the contract every time.

Statutory Liability: The Cost of Missing the Deadline

If a head contractor fails to provide a payment schedule within the required time, they become statutorily liable to pay the full amount claimed by the due date. This exposure flows directly from section 77 statutory liability of the Queensland BIF Act: miss the deadline, and you become liable for the full amount claimed, no matter what the works were actually worth.

Miss the deadline and the fight is no longer about what the work was worth—you have simply lost on a technicality. Failing to meet the deadline removes the head contractor's right to issue an adjudication response defending the valuation of the claim—under section 82(2) of the BIF Act, a respondent who did not give a payment schedule as required must not give an adjudication response—forcing the dispute into a "pay now, argue later" scenario.

Separating Section 82(4) Substantive Prohibitions from Jurisdictional Defences

The adjudication application has landed, and your initial schedule lacked critical details about the subcontractor's delays and defects. You must now determine which arguments are legally barred as "new reasons" and which jurisdictional flaws in the subcontractor's claim might still allow you to defeat the application entirely.

Statutory Prohibitions vs Jurisdictional Arguments

When structuring an adjudication response Queensland, you must distinguish between the substantive restriction that bans adding new reasons for withholding money and the procedural right to challenge the adjudicator's jurisdiction.

The restriction on new reasons focuses on the valuation of the claim—such as late attempts to deduct money for defects, delays, or back-charges that were not previously detailed. Conversely, jurisdictional challenges attack the validity of the payment claim itself or the adjudicator's authority to hear the matter. The practical distinction looks like this:

New reasons (barred under section 82(4)): reasons for withholding payment—such as defects, delays, or back-charges—that were not itemised in your original payment schedule. (This article calls these "substantive" reasons only to distinguish them from jurisdictional arguments; the statutory phrase is simply "reasons for withholding payment.")
Jurisdictional challenges (survive a vague schedule): arguments that the payment claim was invalid, or that the claimant had no available reference date when they invoiced.

The Section 82(4) Bar on Substantive "New Reasons"

A respondent is legally prohibited from introducing new reasons for withholding payment during an adjudication if those reasons were not already included in the payment schedule. This restriction is codified in section 82(4) of the BIF Act, which explicitly bars respondents from attempting to retroactively justify deductions.

Section 82(4) prohibits a respondent from raising any reasons for withholding payment in an adjudication response that were not provided in the original payment schedule. This means that once your response is before the adjudicator—lodged through the QBCC Adjudication Registry, the registry function through which Queensland adjudication applications are administered—the adjudicator must not consider any substantive valuation arguments that do not align with your initial schedule, because section 88(3)(b) directs the adjudicator to disregard a reason that is prohibited under section 82, and section 82(5) permits the adjudicator to require the response to be resubmitted without the new reasons. In effect, it locks the dispute to the reasons you identified within the 15-business-day window—nothing you left out can be added later.

Valid Jurisdictional Challenges Available to Head Contractors

Despite the restrictions on substantive reasons, a head contractor may still raise valid jurisdictional challenges in their adjudication response, even if those challenges were not listed in the payment schedule.

For example, you can argue that the document served does not meet the requirements of a valid payment claim under Queensland's Security of Payments framework, or that the claimant lacked an available reference date when they submitted the invoice. Whether an adjudicator will accept these arguments depends on a strict assessment of the statutory requirements and the specific facts of the project. A successful jurisdictional challenge can invalidate the adjudicator's authority entirely, meaning a court may declare the adjudication decision void regardless of whether your payment schedule was vague or detailed. Where only part of the decision is affected, section 101(4) of the BIF Act allows the court to sever that part and leave the balance binding.

The "Vague Schedule Trap": Why One-Line Deductions Fail at Adjudication

Your project manager withheld $200,000 using a one-line entry reading "defective work" in the payment schedule, and you are now trying to attach a 50-page expert report to the adjudication response. The risk here is that an adjudicator will view the expert report not as supporting evidence, but as an entirely new reason that must be struck out.

Why Generic "Defective Work" Labels Do Not Satisfy Section 69

Example: A head contractor receives a $500,000 progress claim and issues a payment schedule certifying $300,000. In the schedule, the only explanation for the $200,000 shortfall is the phrase "defective work on level three." The subcontractor files an adjudication application. When the head contractor attempts to submit a detailed breakdown showing that the $200,000 consists of specific waterproofing failures, structural misalignment, and acoustic non-compliance, the adjudicator rejects the breakdown.

A valid payment schedule must explicitly state the respondent's reasons for withholding any part of the payment claimed. Under section 69 of the BIF Act, generic labels fail this standard because they do not provide the claimant with sufficient detail to understand why the specific amount was deducted. This failure operates as a critical evidence factor, rendering the schedule too vague to support a detailed defence later.

The Danger of Cross-Referencing Previous Correspondence

Expert insight: The single most common mistake I see is a contract administrator who has been running a dispute over several months copying the phrase "reasons for withholding remain unchanged" from one schedule to the next. It feels efficient. It is a trap.

In Baguley Build Pty Ltd v Olcon Concrete & Construction Pty Ltd & Anor [2025] QSC 126, the head contractor certified $nil and stated only that its reasons "have not changed" from earlier claims. The earlier schedules had actually spelled out real grounds—unsigned timesheets, missing accommodation receipts, downtime, defective work. But because the current schedule did not restate them, the adjudicator treated them as "new reasons" and disregarded the lot. When the head contractor applied to set the decision aside, the Supreme Court refused to intervene—holding that even if the adjudicator had erred in that characterisation, it was an error made within jurisdiction rather than a jurisdictional error, and so was not open to review.

The tactical lesson is blunt. An adjudicator only looks at the schedule in front of them for the claim being adjudicated. They will not go hunting through your file to reconstruct what you meant three claims ago. Even attaching the old correspondence is risky unless the schedule itself expressly adopts and identifies those specific reasons.

Treat every payment schedule as if the adjudicator has never seen a single prior document on the job. If a reason matters, it goes in the current schedule in full—stated fresh, tied to the specific amount, every time. Cross-referencing is not a shortcut; it is how head contractors hand back money they were entitled to withhold.

How Adjudicators Treat Late Expert Reports Under Section 82

When assessing an adjudication application Queensland, adjudicators draw a strict line between evidence that supports an existing reason and the introduction of a new reason masquerading as evidence.

Adjudicators are likely to reject detailed expert reports submitted in an adjudication response if the foundational reasons for those reports were not explicitly stated in the payment schedule. If your initial schedule broadly cited "defective work" without specifying the nature, location, or cost breakdown of those defects, submitting a subsequent expert report detailing waterproofing failures is typically viewed as a new reason rather than supporting evidence. This means that relying on Queensland building and construction lawyers to draft a comprehensive adjudication response cannot cure a fundamentally vague payment schedule.

The practical test an adjudicator applies is whether your expert report is answering a question the schedule already raised, or asking a new one. If your schedule said "waterproofing to level three balconies is defective and non-compliant," a report quantifying that failure is supporting evidence, and it is likely to be read. If your schedule said only "defective work," the same report is introducing the defect for the first time, and it is likely to be struck out as a new reason.

The distinction turns on specificity in the schedule, not on the quality of the report. A brilliant 50-page expert report cannot retrofit a reason that was never articulated. In practice, the schedule should already name the defect, its location, and the dollar figure withheld against it—the report then does the proving, not the pleading. The rule to live by: in every payment schedule, name the defect, state its location, and tie a dollar figure to it, as a matter of course. The schedule pleads the reason; the expert report proves it.

Salvaging Your Position: Final Account Rights Following an Adjudication Loss

The adjudicator has ruled against you because your schedule was too vague, and you are now statutorily compelled to pay a disputed sum. The critical next step is pivoting from the interim adjudication loss to securing your long-term commercial position through subsequent payment cycles or civil action.

Security of Payments: Civil Proceedings and the Preservation of Final Rights

Expert insight: A loss at adjudication due to a defective payment schedule does not permanently extinguish a head contractor's ability to recover the overpayment. Section 101 of the BIF Act operates to preserve final contractual rights and expressly empowers a court or tribunal to order restitution of amounts paid under the adjudication scheme, ensuring that payment rights under the BIF Act remain interim in nature. If you are forced to pay for defective work because your schedule was too vague, you may still pursue a separate avenue of recovery. A court or the Queensland Civil and Administrative Tribunal (QCAT) can order restitution of the amount paid under section 101(3), while a QBCC dispute offers a practical, regulator-led route to address the underlying defective work, though it is not itself a forum for a restitution order.

The BIF Act operates as an interim payment mechanism, meaning head contractors retain the right to recover disputed payments through final civil proceedings. However, whether you can successfully recover those funds relies heavily on the quality of your contemporaneous evidence and the financial viability of the subcontractor at the time of final judgment.

Expert insight: The right to recover is real, but recovery in practice lives or dies on two things—the quality of your contemporaneous evidence and whether the subcontractor is still solvent when you get to judgment. Both are decided long before you file.

Build the file at the time the defect appears, not when the dispute escalates: dated photos, site instructions, independent inspection reports and a clear cost trail for the rectification. That contemporaneous record is what turns a "pay now" loss into a recoverable final claim.

The harder commercial reality is funding and timing. Chasing an overpayment through court or QCAT costs money and takes time, and if the subcontractor has wound up or moved assets in the interim, a favourable judgment can be worth very little. Weigh the likely recovery against the cost of pursuing it before you commit.

Managing the Next Payment Cycle Deductions

If court or QCAT recovery feels too slow and expensive, there is a faster route. While final civil proceedings offer long-term recovery, you can often address a vague schedule error much faster in the very next progress claim cycle.

If an adjudicator strikes out your defect deductions because they were poorly articulated, you can procedurally correct this by issuing a comprehensively drafted payment schedule in the following month. By detailing the specific defects, providing a clear cost breakdown, and attaching the relevant evidence at the time the new schedule is issued, you establish a valid foundation for the deduction. If you are also managing a concurrent EOT claim head contractor, you must apply the same level of detail to the delay cost offsets. To ensure your new schedule avoids the same pitfalls, you should request a consultation early in the assessment window.

Conclusion

The first move, though, is not to draft—it is to triage: check the date your schedule was served against the 15-business-day limit, confirm whether the payment claim and reference date are even valid, and only then work out which of your reasons actually made it into the schedule. However, as the rules of the BIF Act clearly dictate, the administrative shortcut of issuing a vague payment schedule citing only "defective work" cannot be papered over with a detailed adjudication response. If the foundation is missing from the schedule, your expert reports are likely to be struck out as legally barred "new reasons."

You now understand that the 15-business-day statutory limit to issue a schedule overrides longer contractual assessment periods, and that section 82(4) operates as a strict gatekeeper against expanding your substantive arguments during adjudication. While a procedural loss forces you into a "pay now, argue later" position, you also know that jurisdictional challenges remain available and that final civil proceedings can eventually recover funds lost to a poorly drafted document.

Do not wait until the adjudication application arrives to discover your project managers are using one-line deductions. Before the next progress claim lands on your desk, audit your internal payment schedule templates to ensure every deduction explicitly details the reason, the specific location, and the cost breakdown, giving your business the legal foundation it needs to defend the valuation.

If you would like a second set of eyes on that process, our construction team can review your existing payment schedule templates and stand ready to assist during the critical 15-business-day window. Request a consultation before your next claim falls due—the cost of getting the schedule right is a fraction of the sum you stand to lose by getting it wrong.

FAQs

What is the maximum timeframe to provide a payment schedule in Queensland?

Head contractors must serve a payment schedule within the timeframe specified by the contract, or a maximum of 15 business days after receiving the claim, whichever is earlier. Contractual clauses attempting to extend this period beyond 15 business days are ineffective to extend the deadline, because section 76 requires you to comply with whichever period ends first, and section 200 of the BIF Act prevents parties from contracting out of the Act's requirements.

What happens if I miss the 15-business-day deadline for a payment schedule?

If a head contractor fails to provide a payment schedule within the required statutory time, they become liable to pay the full amount claimed by the due date. This procedural default typically prevents you from disputing the valuation of the claim in an adjudication, forcing a "pay now, argue later" outcome.

Can I add new reasons for withholding payment in my adjudication response?

No, section 82(4) of the BIF Act explicitly prohibits a respondent from raising any reasons for withholding payment in an adjudication response that were not provided in the original payment schedule. Any attempt to introduce new substantive reasons at the response stage is likely to be disregarded by the adjudicator.

Is it sufficient to state "defective work" as a reason for withholding payment?

Using a generic label like "defective work" is often insufficient to satisfy the requirements of a valid payment schedule under Queensland law. An adjudicator may reject subsequent expert reports detailing the defects if the original schedule lacked a specific explanation and cost breakdown of the deductions.

Can I just reference previous emails as my reason for withholding payment?

Relying on cross-references to past correspondence or simply stating "reasons remain unchanged" is a high-risk strategy that adjudicators frequently reject. The Supreme Court of Queensland has indicated that each payment schedule should explicitly detail the reasons relevant to the current claim to avoid being struck out for non-compliance.

Does losing an adjudication mean I can never recover the overpayment?

Losing an adjudication due to a defective payment schedule does not permanently extinguish your ability to recover the funds. The BIF Act operates as an interim payment mechanism, meaning you may still pursue final contractual rights or initiate civil proceedings in Queensland to recover the overpayment.

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