Ontario Construction Act: Liens, Holdback and Prompt Payment

Ontario Construction Act: Liens, Holdback, Prompt Payment, Trust Funds and Adjudication
Many people still search for the “Construction Lien Act,” but Ontario’s current statute is the Construction Act. It covers much more than liens. It regulates statutory holdback, trust funds, proper invoices, prompt-payment deadlines and interim construction adjudication.
The Act works through the contract, invoices and payment records
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“Construction Lien Act” or “Construction Act”?
The current name is the Construction Act. Ontario’s reforms changed the statute’s name and modernized lien and holdback rules. Prompt-payment and adjudication provisions came into force on October 1, 2019. Further amendments came into force on January 1, 2026.
The older name remains a useful search phrase, but the page should not imply that a separate “Construction Lien Act 2025” remains in force.
Official sources: Ontario Construction Act, O. Reg. 304/18 and Ontario Dispute Adjudication for Construction Contracts.
1. Construction liens
A person who supplies qualifying services or materials to an improvement may have a lien under the Act. The lien can operate as a charge against statutory holdback and certain unpaid contract amounts, and it may attach to an interest in the land.
The deadline differs by claimant and can be affected by substantial performance, completion, abandonment, termination, last supply, subcontract certification and annual holdback-release notices.
2. The 10% statutory holdback
Each payer under a contract or subcontract where a lien may arise must retain a basic holdback equal to 10% of the price of services or materials as they are actually supplied. The obligation applies whether the agreement uses progress payments or one payment at completion.
| Illustrative invoice | Basic holdback | Amount before other deductions | What still requires checking |
|---|---|---|---|
| $100,000 before HST | $10,000 | $90,000 | HST, deficiencies, prior payments, written lien notices and lender reserves |
The statutory holdback is not simply a permanent deficiency fund. Contract rights for incomplete or deficient work should be addressed separately.
3. Mandatory annual holdback release
Under the current regime, the owner must address accrued basic holdback after each anniversary of the date the contract was entered into.
Within 14 days after the anniversary
The owner publishes the prescribed notice of annual release of holdback, Form 6, stating the amount intended to be paid and the intended payment date.
Construction trade news website
O. Reg. 304/18 requires the notice to be published on a construction trade news website.
At least 60 and no later than 74 days
The owner pays the accrued holdback for the preceding year within the statutory window after publication, unless a preserved or perfected lien prevents release.
Contractor and subcontractor payments follow
The Act establishes corresponding downstream holdback-payment deadlines.
4. Proper invoices and prompt payment
Where the prompt-payment provisions apply, a proper invoice starts the statutory payment process. The Act identifies required invoice information and permits contracts to require additional accounts-payable information within statutory limits.
From January 1, 2026, an invoice that does not meet the proper-invoice requirements is deemed proper unless the owner identifies the deficiency and what is needed to correct it in writing within seven days after receipt.
The downstream rules are more detailed when the owner pays only part of the invoice or does not pay. Contractors and subcontractors may need prescribed notices and, in some circumstances, adjudication.
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5. Construction trust funds
The Act’s trust provisions are separate from lien rights. In general terms, certain amounts received or owing on account of an improvement are trust funds for the benefit of contractors, subcontractors and suppliers who remain unpaid.
Project funds cannot be used inconsistently
Amounts received by an owner for financing an improvement, subject to statutory deductions, can constitute a trust for the contractor.
Money is held for unpaid downstream parties
Amounts owing to or received by contractors and subcontractors on account of the project can constitute trust funds.
Accounting matters
Contractors and subcontractors have statutory recordkeeping duties relating to trust funds.
Holdback amounts expressly included
The current provisions expressly address holdback amounts owed to or received by contractors and subcontractors.
A party can lose the lien remedy and still face or pursue a contract or trust claim. They are different legal routes with different proof and limitation issues.
6. Interim construction adjudication
Adjudication provides a faster, interim-binding process for eligible construction disputes. It is administered by ODACC, Ontario’s authorized nominating authority.
Disputes that may be referred can include:
- valuation of services or materials;
- payment under the contract or subcontract;
- approved, disputed or proposed change orders;
- notices of non-payment;
- set-off and holdback issues identified by the current Act;
- other matters agreed by the parties or prescribed.
The January 1, 2026 regime includes current rules for registry adjudicators and private adjudicators under the Act and O. Reg. 264/25.
7. What an owner should have in the construction contract
- Complete scope, exclusions, allowances and contract-document list
- Proper-invoice delivery address and required information
- Payment dates aligned with lender draw timing
- Statutory holdback shown separately on invoices
- Annual holdback notice and administration responsibility
- Written change-order pricing and schedule procedure
- Evidence supporting each progress payment
- Trust, records and statutory-declaration requirements where appropriate
- Adjudication, court, arbitration and negotiation clauses that do not attempt to waive the Act
- Separate deficiency, set-off, final-payment and warranty provisions
See What Should a Good Construction Contract Include? and Home Construction Loan Draw Schedule.
Two existing books for planning the project before the money moves
Both downloads remain available at their current prices. Unsupported comparison values have been removed.
The Ontario Building Permit Bible
A practical guide to the application order, complete-document requirements, municipal review and inspection preparation.
- Complete-application checklist
- Who to hire and in what order
- Permit-fee planning
- Inspection preparation
The Ontario Lot-Buying Bible
A 28-page guide covering buildability, site work, financing, HST, allowances and contingency.
- Site-cost planning worksheets
- Complete-project budget categories
- Buildable-lot checklist
- Go/no-go scorecard
Buying land and building on it? Get both.
Plan the property and budget, then work through the permit and inspection process.
Contract Centre and related guides
Ontario Construction Act FAQ
Is it the Construction Lien Act or the Construction Act?
The current name is the Construction Act. People still use the older name because liens remain an important part of the statute, but the Act also covers holdback, trusts, prompt payment and adjudication.
How long do I have to register a construction lien?
The modern general preservation period is 60 days after the applicable statutory trigger, followed by a general 90-day perfection period. The trigger and transition rules require legal analysis.
What is the 10% holdback?
It is the basic statutory holdback each payer must retain from the price of services or materials as they are actually supplied where a lien may arise.
What changed on January 1, 2026?
Major changes included mandatory annual release of accrued basic holdback, new proper-invoice deeming rules, express trust treatment of holdback amounts and updated adjudication administration.
What happens if an invoice is missing required information?
Under the current deeming rule, it can still become a proper invoice unless the owner gives written notice of the deficiency and what is needed to correct it within seven days after receipt.
Does the owner always have 28 days to pay?
Where the prompt-payment provisions apply, the owner generally pays the payable amount under a proper invoice within 28 days or gives the prescribed notice of non-payment within 14 days. Holdback requirements still apply.
What is adjudication?
It is a faster, interim-binding process for eligible construction disputes. ODACC administers Ontario adjudications under the Act.
Can a contract waive the Construction Act?
No. The Act states that an agreement is not binding to the extent it provides that the Act does not apply or that its remedies are unavailable.
Not legal advice. This page is a plain-language overview. Always confirm the current statute, regulations, transitional rules and project-specific deadlines with an Ontario construction lawyer.
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Upload My Documents for the Free ScanReviewed July 29, 2026. General educational information only. This page does not issue notices, calculate deadlines, preserve liens, commence adjudications or provide legal advice.
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