Ontario Construction Act 2026: Prompt Payment, Adjudication & Holdbacks, What Contractors, Subcontractors & Owners Must Know

The Ontario Construction Act changes that took effect on January 1, 2026, represent the most significant overhaul of construction payment and dispute-resolution law in the province in decades. Driven by amendments under Bill 60 and supported by new regulations including O. Reg. 264/25, the reforms introduce a comprehensive prompt payment regime, broaden access to adjudication for a wider range of project participants, and mandate an annual release of holdback that fundamentally alters cash-flow dynamics on every Ontario construction project. Whether you are an owner, general contractor, subcontractor, surety or in-house counsel, the compliance decisions you make now will determine whether you capture the benefits of faster payment cycles, or face costly disputes under an enforcement framework that carries real teeth.

At-a-Glance: Key Ontario Construction Act Changes Effective January 1, 2026

Before diving into the details, here is a 30-second checklist of what changed when the 2026 amendments came into force under the Construction Act, R.S.O. 1990, c. C.30:

• Prompt payment regime. Owners must pay a proper invoice within a prescribed timeline; each downstream payer must then pay within defined windows, creating a cascading payment waterfall.
• Redefined “proper invoice.” The Act now prescribes specific content requirements that an invoice must satisfy before the payment clock starts running.
• Broadened adjudication access. More categories of construction disputes, including those involving subcontractors, suppliers and parties joined to the process, can now be referred to interim adjudication, expanded by O. Reg. 264/25.
• Mandatory annual holdback release. Owners and contractors must release accumulated holdback on an annual basis rather than retaining it until project completion, subject to lien preservation rules.
• Strengthened trust and payment-mechanics provisions. Enhanced statutory trust obligations require more rigorous tracking and segregation of construction funds.
• Lien-period adjustments. Preservation and perfection timelines have been recalibrated to work alongside the new annual holdback release cycle.
• Supporting regulations and forms. New prescribed forms, invoice templates and procedural regulations underpin the operational requirements of each reform pillar.

Industry observers expect these changes to accelerate payment timelines significantly, but only for project teams that update their contracts, invoicing procedures and internal controls before disputes arise. The sections below break down each pillar of reform with the timelines, checklists and drafting guidance that construction law practitioners are advising clients to implement immediately.

Prompt Payment in Ontario: Proper Invoice, Deadlines & AP Procedures

What Is a “Proper Invoice” Under the Amended Act?

The prompt payment framework hinges on the concept of a proper invoice Ontario contractors must issue before any payment deadline begins to run. Under the amended Construction Act, a proper invoice must contain prescribed information to be valid. The following checklist summarises the required fields:

If an invoice does not include all prescribed content, the recipient is entitled to return it with a notice of non-compliance, which stops the payment clock. Practitioners note that even minor omissions, such as a missing project identifier, can reset the entire timeline. Getting the proper invoice right on first submission is the single most important operational step under the new regime.

Payment Clock & Construction Payment Deadlines

Once a compliant proper invoice is received, the Act imposes strict construction payment deadlines on each level of the contractual chain. The payment waterfall operates as follows:

Where an owner fails to pay or issue a proper notice of non-payment within the prescribed window, the invoice amount is deemed payable and interest accrues at the rate prescribed by regulation. The deemed-invoice mechanism described by Norton Rose Fulbright means that silence or administrative inaction by the payer is no longer a neutral event, it is an automatic trigger for payment obligations and potential adjudication.

AP Process Map & Avoidance Checklist

Accounts-payable departments must redesign their workflows to meet the new construction payment deadlines. The following step-by-step AP playbook reflects what experienced practitioners are recommending to clients:

• Step 1, Receipt logging. Log the date of invoice receipt immediately. This date starts the 28-day clock for owners.
• Step 2, Completeness review. Within 48 hours, verify the invoice against the proper invoice checklist above. If any field is missing, issue a written notice of non-compliance within 14 days.
• Step 3, Substantive review. If the invoice is complete but the amount is disputed, issue a notice of non-payment specifying the disputed and undisputed portions within the 14-day window.
• Step 4, Pay undisputed amounts. Regardless of any dispute, pay the undisputed portion by Day 28.
• Step 5, Downstream notification. GCs should alert subcontractors of payment status no later than Day 30, ensuring the 7-day cascading payment can be processed on time.
• Step 6, Record retention. Retain all notices, date-stamps and correspondence in a project-specific file, this evidence is essential if an adjudication is commenced.

Failing to issue a timely notice of non-payment is one of the most consequential errors under prompt payment Ontario rules. Early indications suggest that many disputes reaching adjudication in Q1 2026 have involved missed notice windows rather than substantive valuation disagreements.

Adjudication in Ontario: Who Can Apply, Process, Timelines & Enforcement

Who Can Commence Adjudication and Expanded Access

One of the most significant Ontario Construction Act changes is the broadening of adjudication Ontario parties can access. Prior to January 1, 2026, adjudication under Part II.1 of the Act was limited in scope. The 2026 amendments, reinforced by O. Reg. 264/25, expand eligibility so that virtually any party in the construction pyramid, including subcontractors, sub-subcontractors, suppliers and, in certain circumstances, sureties joined to the proceeding, can refer a payment dispute to an adjudicator. Joinder provisions now permit related parties to be brought into the same adjudication, reducing the risk of inconsistent outcomes across parallel disputes on the same project.

Adjudication Timeline & Procedural Steps

The adjudication process follows a compressed timeline designed to produce interim binding decisions quickly. The typical procedural flow is set out below:

The entire process, from notice to decision, is designed to conclude within approximately 30 to 46 days. Industry observers expect the compressed timelines to push parties toward earlier resolution, since the cost of a full adjudication is modest relative to arbitration or litigation but the outcome is enforceable immediately on an interim basis.

Enforcing Adjudication Decisions and Interplay with Liens and Arbitration

An adjudicator’s determination is binding on an interim basis. If the losing party fails to comply, the successful party can enforce the decision as if it were a court order by filing with the Superior Court of Justice. This enforcement mechanism gives adjudication decisions practical teeth that earlier voluntary processes lacked.

Critically, commencing an adjudication does not extinguish lien rights. A party may preserve and perfect a construction lien under Part IV of the Construction Act while simultaneously pursuing or defending an adjudication. Similarly, adjudication does not preclude a subsequent arbitration or court proceeding on the same dispute, the adjudication decision remains binding only until a court, arbitral tribunal or subsequent agreement of the parties resolves the matter finally.

For practical enforcement purposes, parties should:

• Diarise the 10-day compliance window immediately upon receiving a determination.
• If the respondent does not pay, file for court enforcement without delay, delay can prejudice creditor rights.
• Preserve lien rights independently by registering the claim for lien within the applicable lien period, regardless of adjudication status.
• Consider whether surety bonds Ontario projects require are triggered by the determination and provide the necessary notice to the surety within any contractual notice windows.

Holdbacks, Trusts & Liens: Annual Release Mechanics and Effect on Cash Flow

Mandatory Annual Holdback Release, Triggers and Calculations

The introduction of a mandatory annual holdback release is among the most consequential amendments for project cash flow. Under the prior regime, owners retained the statutory holdback (typically 10% of each progress payment) until the project reached substantial performance, which could lock up significant capital for years on large projects. The 2026 amendments require owners to release accumulated holdback on an annual basis, calculated from the anniversary of the date when holdback obligations first arose on the project.

The release is triggered once the applicable lien period for the work done during that annual cycle has expired without any liens being preserved. If a lien has been preserved, the owner may retain sufficient holdback to cover the lien claim but must release the balance. This mechanism means that subcontractors and suppliers should see holdback funds returned far earlier in the project lifecycle, a material improvement for firms that previously carried working-capital shortfalls throughout multi-year projects.

Trust and Payment Mechanics, Protections for Subcontractors

The 2026 amendments also strengthen the statutory trust provisions that protect subcontractors and suppliers. All amounts received by an owner, contractor or subcontractor on account of the contract price constitute a trust fund for the benefit of those below them in the contractual chain. The reforms clarify that trust obligations attach to holdback amounts during the annual retention period, meaning that owners cannot commingle or use holdback funds for unrelated purposes without risk of a trust breach claim.

For subcontractors, the practical effect is twofold: faster access to holdback through the annual release cycle, and stronger legal remedies, including potential personal liability for directors, if trust funds are diverted. Canadian construction lawyers are advising subcontractors to request annual trust-fund status reports from owners and GCs to verify that funds are being held in compliance with the Act.

How Construction Liens Ontario Mechanics Have Changed

The lien framework under the Construction Act has been recalibrated to align with the annual holdback release cycle. Under the previous rules, lien preservation and perfection timelines were anchored to project milestones such as substantial performance or contract completion. The 2026 amendments retain these anchors but add an annual-cycle dimension: because holdback is now released annually, the lien window for each annual tranche opens and closes independently.

This means that a subcontractor who fails to preserve a lien within the prescribed period for a given annual holdback release may lose recourse against that tranche of funds, even if the project is still ongoing. The likely practical effect will be that subcontractors must track lien deadlines on a rolling annual basis rather than waiting for a single project-wide triggering event.

The following comparison table summarises how the three core obligations interact under the 2026 regime:

Construction Contract Changes Ontario: Drafting & Operational Updates

Sample Prompt-Payment Clause (Redline)

Existing contracts that pre-date January 1, 2026, should be reviewed for compliance. A typical redline to a payment clause might read:

“The Owner shall pay the Contractor within 30 calendar days 28 days of receipt of a proper invoice as defined in section 6.1 of the Construction Act, R.S.O. 1990, c. C.30. Where the Owner disputes any portion of the invoice, the Owner shall deliver a notice of non-payment within 14 days of receipt of the proper invoice, specifying the disputed and undisputed amounts. The undisputed amount shall be paid within the 28-day period regardless of the dispute.“

This redline ensures the contract mirrors the statutory requirements. Any contractual payment term that purports to extend the 28-day window or waive the prompt payment regime is likely unenforceable given the Act’s mandatory framework.

Adjudication Clause & Opting-In Mechanics

Contracts should now expressly reference the adjudication provisions of the Act. A recommended clause:

“Any dispute arising under this contract that is eligible for adjudication under Part II.1 of the Construction Act shall be referred to adjudication in accordance with the Act and applicable regulations. The parties consent to the jurisdiction of the Authorized Nominating Authority and agree to comply with any interim determination within 10 days of its issuance.”

While adjudication is a statutory right that does not require contractual consent, including an express clause reduces procedural friction and manages expectations for all parties from the outset.

Practical AP/Invoice Templates & Recommended Internal Controls

Project teams should implement the following internal controls to comply with the construction contract changes Ontario projects now require:

• Adopt a standardised proper invoice template that includes every prescribed field, and distribute it to all subcontractors at project kick-off.
• Configure AP software to auto-flag any invoice that is missing required fields and generate a non-compliance notice within 48 hours.
• Maintain a centralised deadline tracker, ideally integrated with project management software, that calculates the 28-day, 14-day and 7-day deadlines automatically upon invoice receipt.

Impact on Surety Bonds Ontario Projects & Lender Risk Mitigation

The annual holdback release and broadened adjudication access create new risk vectors for sureties and construction lenders. Surety bonds Ontario projects rely upon are typically structured around the assumption that holdback remains intact until project completion, providing a financial cushion against deficiency claims. The mandatory annual release reduces that cushion incrementally, increasing the surety’s potential exposure to performance and payment bond claims earlier in the project lifecycle.

Sureties should take the following steps to mitigate risk:

• Monitor annual holdback releases. Request written confirmation from the principal and obligee each time holdback is released, verifying that no unpreserved liens exist.
• Update notice provisions. Ensure bond forms require the obligee to notify the surety promptly of any adjudication commenced on the bonded project, particularly where joinder may bring the surety into the proceeding.
• Reassess bonding capacity. Factor the accelerated release of holdback into underwriting models, since the effective financial backstop on multi-year projects is now smaller at any given point.
• Review indemnity agreements. Confirm that general indemnity agreements with principals address the new trust obligations and annual release mechanics to avoid gaps in indemnity coverage.

Lenders with security interests in construction receivables should similarly update their monitoring protocols, as the annual release changes the timing and quantum of funds flowing through the project waterfall.

Practical Compliance Checklist by Role

Use this role-based checklist to confirm your organisation has addressed the most critical Ontario Construction Act changes:

• Owners: Update payment clauses; implement 28-day payment tracking; train AP staff on notice-of-non-payment requirements; schedule annual holdback release reviews.
• General Contractors: Verify subcontract payment terms comply with the 7-day cascading deadline; adopt a standardised proper invoice template; establish adjudication response protocols.
• Subcontractors: Ensure every invoice meets the proper invoice requirements; diarise annual holdback release dates and corresponding lien-preservation deadlines; understand how to commence adjudication.
• Sureties: Update bond forms for adjudication notice and joinder provisions; monitor annual holdback releases; recalculate exposure on multi-year projects.
• In-house Counsel: Audit all active contracts for compliance; brief project teams on new timelines; consult construction law specialists on redline and template updates; ensure document-retention policies capture all notices.

Real-World Scenarios: How to Respond Under the 2026 Amendments

The following anonymised scenarios illustrate how the reforms play out in practice and what steps project teams should take:

• Scenario 1, Delayed payment by owner. A subcontractor submits a proper invoice on Day 1. The owner takes no action for 30 days. Because no notice of non-payment was issued within 14 days, the full amount is deemed payable and interest accrues. The subcontractor may immediately commence adjudication to recover the amount plus interest. Lesson: owners must diary the 14-day notice window or face automatic liability.
• Scenario 2, Adjudication request on a mid-project dispute. A general contractor disputes the valuation of a change order. The subcontractor files a notice of adjudication. An adjudicator is appointed within 7 days and issues a determination in 28 days ordering the GC to pay the disputed amount. The GC complies within 10 days but preserves the right to challenge the determination in a subsequent arbitration. Lesson: adjudication produces fast, enforceable results, but is not the final word, parties should plan their long-term dispute strategy accordingly.
• Scenario 3, Holdback release contested. An owner attempts to withhold the annual holdback release, citing general concerns about workmanship. No lien has been preserved against the relevant annual tranche. Because no lien exists, the owner is obligated to release the holdback. The subcontractor’s counsel sends a demand letter citing the mandatory release provisions, and the owner releases funds within 10 days. Lesson: general quality concerns do not override the statutory release obligation, only a preserved lien or prescribed statutory exception permits withholding.

Conclusion: Acting on the Ontario Construction Act Changes

The Ontario Construction Act changes effective January 1, 2026, are not optional compliance items, they are mandatory obligations backed by enforceable deadlines, adjudication rights and court enforcement mechanisms. Every project participant, from owners and general contractors to subcontractors, sureties and lenders, must update their contracts, invoice templates, AP workflows and dispute-response protocols to align with the new framework. Organisations that treat these reforms as a back-office administrative update risk missed deadlines, deemed-payment obligations and costly adjudications. Those that invest in compliance infrastructure now will benefit from faster cash cycles, clearer dispute pathways and stronger contractual relationships. To discuss how these amendments apply to your specific project or portfolio, find a Canadian construction lawyer through the Global Law Experts directory.

Last reviewed: May 14, 2026

Sources

1. e-Laws: Construction Act, R.S.O. 1990, c. C.30 (consolidation)
2. BLG, Changes to Ontario’s Construction Act
3. Blake, Cassels & Graydon, Amendments now in force
4. Fasken, Amendments take effect Jan 1, 2026
5. Dentons, Construction Act amendments now in force
6. Norton Rose Fulbright, Invoices to be deemed
7. Osgoode Professional Development, Critical Updates for Construction Law and Practice in Ontario 2026
8. Gowling WLG, Understanding the impact of Ontario’s Construction Act changes
9. Aird & Berlis, Ontario’s Bill 60: Key Changes to the Construction Act Arriving in 2026
10. McMillan LLP, Legislative Reforms to Ontario’s Construction Act