Almost nobody loses a lien by miscounting to sixty. They lose it by starting the count on the wrong day.
Ontario's Construction Act gives you 60 days to preserve a lien, and a further 90 days to perfect it by commencing an action and registering a certificate of action. Neither period can be extended. Not by agreement between the parties, not by a judge, not by a course of dealing where everybody has been paid late for years without complaint.
What makes that dangerous is not the arithmetic. It is that people assume the 60 days runs from their last day on site, and for a great many claimants it does not. Section 31 assigns the trigger for you, based on two things: what your role on the project was, and whether the work was supplied before or after substantial performance of the contract. It is not a question of fact about your contract and it is not a choice among options.
If you are the contractor: section 31(2)
For all work supplied on or before the date of substantial performance, your 60 days runs from publication of the certificate or declaration of substantial performance. For work supplied after that date, it runs from completion, abandonment or termination of the contract.
Read that again if you are a contractor, because last supply is not a trigger for you at all. Your clock can have started months before you left site, on a date fixed by a document somebody else published. Contractors who diarise their last day on site are diarising a date the Act does not use.
If you are anyone else: section 31(3)
Subcontractors and suppliers work off a different provision. For work supplied on or before the date of substantial performance, the 60 days again runs from publication of the certificate or declaration. For work after that date, it runs from the earlier of your last supply and certification of the subcontract under section 33.
The consequence catches people out: your lien can be split across two expiry dates. The portion covering work before substantial performance can die on one date while the balance is still live on another. If a certificate was published while you were still on site, you may already have lost part of your claim without anything visible having happened.
What counts as supply, when supply is the trigger
Where last supply does govern, the trap is what counts. Returning to site to fix a deficiency, to collect equipment, or to do warranty work generally does not restart the clock, because it is not a fresh supply to the improvement. Contractors who assume a callback in June resets a deadline that expired in May lose liens this way every year. A genuine additional scope of work performed at the owner's request is different: that is supplying something new rather than finishing what you already owed.
Termination, and the notice that starts the clock
Where a contract is terminated rather than completed, termination starts the clock for post-substantial-performance work. A notice of termination must be published within 7 days of termination, and where more than one is published, it is the first that governs lien expiry. On a project that has gone badly the date of termination is frequently disputed, and whether a notice was published, and when, is a registry question rather than something to take on trust.
On public work, do not register at all
Preserving normally means registering a claim for lien against title. On Crown land, municipal land, and railway rights of way, the lien does not attach to the land, so there is nothing to register against and a registered claim is not a preserved lien. You preserve instead by giving written notice of lien to the owner within the same 60 days, under sections 16(3) and 34(3). On Crown premises the notice goes to the prescribed office; on municipal premises, to the clerk.
If you are working on a school, a hospital, a courthouse, a transit project or a city facility, establishing who owns the land is a day-one question. A subcontractor who registers against title on a public job and discovers the error on day sixty-five has no lien and no way back.
The 90 days does not run from when you registered
One more piece of arithmetic people get backwards. The 90-day perfection window runs from the last day on which the lien could have been preserved, not from the day you actually registered it. Preserving early does not shorten it: register on day 10 and you still have until day 150. Note also that an unperfected lien expires but does not come off title by itself, so it stays registered until discharged or vacated by court order.
What actually happens if you miss it
You lose the security, not the debt. The contract claim survives and can be sued on in the ordinary way, and depending on timing you may still be able to commence an adjudication. What disappears is the leverage.
That distinction is the whole of the practical difference. A registered lien stops an owner refinancing, closing a sale, or drawing the next advance under construction financing, and lenders will not fund over it. An unsecured invoice does none of that. The same claim, brought on day fifty-five, is a negotiation with a party that needs clear title. Brought on day seventy, it is debt collection against a company that may not be there in eighteen months.
What to do this week if you are unpaid
- Check whether substantial performance has been published, first. It decides which trigger applies to you, and it may already have started your clock.
- Establish who owns the land. If it is Crown, municipal, or a railway right of way, you preserve by written notice to the owner, not by registering against title.
- Fix your last supply date from records rather than memory: delivery slips, site sign-ins, dated photographs, the last invoice for work actually performed.
- Search title. Prior mortgage advances can reduce what a lien is worth, though the section 78 priority rules are more favourable than most claimants assume, so this is a reason to check the advance history rather than to give up.
- Separate what is genuinely lienable, being the value of services and materials supplied, from delay and lost profit claims, which largely belong in the action rather than in the lien amount.
- Get advice while there is still time to act on it. Almost every construction file I see arrives late.
More detail on process, holdback and adjudication is on the construction lien page, and there is a step-by-step guide at what to do when you are unpaid on a construction job.
