Construction Law

Ontario Construction Liens Guide 2024

Construction Act, Holdbacks, Prompt Payment, and Lien Discharge

December 2024 · 14 min read

Ontario construction liens are governed by the Construction Act (formerly the Construction Lien Act, substantially amended in 2018 and in force for new contracts from 2019). The Act creates a statutory lien right for contractors, subcontractors, and suppliers who improve real property — a lien against the owner's interest in the land that must be preserved and perfected within strict timelines. This guide covers lien timelines (45-day preservation, 90-day perfection), mandatory holdback obligations, trust provisions, the prompt payment and adjudication regime, and lien vacating procedures.

Critical Construction Lien Timelines Under the Construction Act

Construction lien timelines are strictly enforced — missing the 45-day preservation deadline extinguishes the lien right entirely. There is no power to extend or excuse a missed lien preservation deadline.

EventDeadlinePartyConsequence of Missing
Substantial performance declaredTriggered by prime contractorPrime contractor / ownerStarts 45-day lien period for most parties; holdback release period begins
Preserve lien (registration or filing)Within 45 days of last supply OR 45 days of substantial performance publicationAll lien claimants (contractors, subcontractors, suppliers)Failure to preserve extinguishes lien right; no extension available
Perfect lien (commence action)Within 90 days of preservationLien claimantFailure to perfect extinguishes lien; action on contract may survive
Set action down for trialWithin 2 years of preservationLien claimantFailure to set down may result in dismissal for delay; lien action is set down in Superior Court
Holdback released to prime contractor45 days after publication of substantial performance (if no liens)OwnerIf liens exist, holdback held until liens resolved; owner personally liable to lien claimants if holdback released prematurely
Prompt payment — owner to prime28 days from proper invoiceOwnerNotice of Non-Payment required if not paying; failure triggers right to adjudication
Prompt payment — prime to subcontractor7 days from receipt of owner paymentPrime contractorNotice of Non-Payment required; failure triggers adjudication right

Mandatory Holdback Obligations: Construction Act s.22

The 10% mandatory holdback applies at every level of the construction pyramid — owner to prime contractor; prime contractor to subcontractor; subcontractor to sub-subcontractor. Failure to maintain holdback creates personal liability for the payer.

10% mandatory holdback

Every payer must retain 10% of the price of each payment for services or materials under a contract or subcontract

Example: Owner pays prime contractor $100,000 progress payment — must retain $10,000 in holdback; prime pays sub $50,000 — must retain $5,000

Holdback is a lien fund

The holdback is held as a fund available to satisfy valid liens; payer cannot apply holdback to other debts or set-offs

Example: If sub has a valid $8,000 lien, the prime's holdback from the owner may be applied to satisfy it

Basic holdback release (after substantial performance)

The basic holdback may be released 46 days after publication of a certificate of substantial performance if no liens are registered

Example: Substantial performance published March 1; no liens registered by April 15; owner may release holdback to prime

Finishing work holdback

Separate holdback for finishing work (work done after substantial performance); released 45 days after completion of the entire contract

Example: Post-substantial-performance finishing work — additional 10% holdback on those payments until contract completion

Personal liability for failure to maintain holdback

Owner who releases holdback prematurely or fails to maintain holdback is personally liable to lien claimants up to holdback amount

Example: Owner pays full price to prime before holdback period expires; sub registers lien; owner liable to sub up to 10% even though already paid prime

Trust Provisions Under the Construction Act

The Construction Act creates statutory trust obligations at each level of the construction pyramid. These trusts operate in addition to lien rights and provide an additional remedy for unpaid suppliers and subcontractors.

  • Owner's trust (s.8): An owner who receives payment from a mortgagee or lender holds those funds in trust for the benefit of the prime contractor, subcontractors, and suppliers to the extent of amounts owing
  • Prime contractor's trust (s.8): A contractor who receives payment holds those funds in trust for subcontractors and suppliers; must not apply trust funds to other debts or obligations
  • Subcontractor's trust: Similar trust obligations apply at the subcontractor level for payments received from the prime
  • Director/officer liability: Directors and officers who participate in or authorize a breach of trust may be personally liable; this is a significant risk for construction company principals
  • Insolvency overlay: Construction Act trusts may take priority over secured creditors in insolvency if the trust funds are traceable; court decisions on priority between Construction Act trust claimants and PPSA secured creditors are complex

Prompt Payment and Adjudication

Prompt Payment Timeline

  • 28 daysOwner pays prime contractor from proper invoice
  • 7 daysPrime pays subcontractor from receipt of owner payment
  • 7 daysSubcontractor pays sub-subcontractor
  • !Payer must give Notice of Non-Payment with reasons if not paying within deadline
  • !Applies to contracts entered into after October 1, 2019

Adjudication Process

  • 1.Party refers dispute to Ontario Dispute Adjudication for Construction Contracts (ODACC)
  • 2.ODACC appoints adjudicator within 7 days
  • 3.Adjudicator decides within 30 days of referral (or 21 days from respondent's response)
  • 4.Determination is binding and immediately enforceable (as court order on leave)
  • 5.Final determination by arbitration or litigation after project completion

Frequently Asked Questions: Ontario Construction Liens

What is the deadline to preserve a construction lien in Ontario?

Under the Construction Act s.31, a lien must be preserved (registered on title or filed with court) within 45 days of the date of last supply of services or materials to the improvement (for subcontractors and suppliers) or within 45 days of publication of a certificate of substantial performance (for prime contractors). Missing the 45-day preservation deadline extinguishes the lien right.

What is the mandatory holdback requirement under the Ontario Construction Act?

Under Construction Act s.22, every payer (owner, prime contractor, subcontractor) must hold back 10% of the price of services and materials supplied under a contract or subcontract. The holdback is retained for the applicable lien period after publication of a certificate of substantial performance. The holdback fund is available to satisfy valid liens. Failure to maintain holdback makes the payer personally liable to lien claimants up to the holdback amount.

How does the Ontario prompt payment regime work?

Under the Construction Act prompt payment provisions (in force since October 2019 for new contracts): the owner must pay the prime contractor within 28 days of receiving a proper invoice; the prime contractor must pay subcontractors within 7 days of receiving owner payment; subcontractors must pay sub-subcontractors within 7 days of receiving payment. If payment is not made, the payer must give a Notice of Non-Payment with reasons within the payment period. Disputes may be referred to adjudication.

How is a construction lien vacated or discharged in Ontario?

A construction lien may be vacated by: (1) court order under Construction Act s.44 (lien not properly preserved, untimely, or no arguable case); (2) payment into court — owner or contractor pays the lien amount into court, court orders lien vacated; (3) posting of security (letter of credit or bond) in lieu of lien amount — court orders lien vacated; or (4) settlement agreement between the parties with discharge registered on title. The most common commercial approach is payment into court or posting of security to remove the lien from title while the underlying claim proceeds.

Track Construction Lien Deadlines with Atticus

Atticus tracks 45-day preservation deadlines, 90-day perfection deadlines, holdback release dates, prompt payment timelines, and adjudication dates for Ontario construction law files. AI document analysis extracts key dates from contracts, invoices, and certificates automatically.

Try Atticus Free for 14 Days