Construction lien deadlines: Ontario and Alberta 60 days, BC 45

A construction lien is the only security most subcontractors have, and it dies on a date fixed by the province where the building stands. Not where your office is. Not where you signed. Where the land is.

The three common-law provinces below use three different clocks, and none of them is close to another. Ontario counts 60 days and then another 90. Alberta counts 60, or 90 if there is concrete involved. British Columbia counts 45 and then gives you a year to sue.

An article quoting one number would be wrong twice out of three times. Here are the three, with the sections.

The three regimes at a glance

Ontario: two stages, and they are not the same thing

Ontario separates preserving a lien from perfecting it, and losing either one loses the lien.

Stage one — expiry and preservation. Section 31(1): "Unless preserved under section 34, the liens arising from the supply of services or materials to an improvement expire as provided in this section."

For a contractor (s. 31(2)), the lien for services or materials supplied on or before the date certified or declared to be the date of substantial performance "expires at the conclusion of the 60-day period next following the occurrence of the earlier of":

• the date a copy of the certificate or declaration of substantial performance is published as provided in section 32, and
• the date the contract is completed, abandoned or terminated.

Where there is no certification or declaration, or for work supplied after that date, the 60 days run from the earlier of the date the contract is completed and the date it is abandoned or terminated.

For anyone else (s. 31(3)) the 60 days run from the earliest of four events: publication of the certificate or declaration; the date that person last supplied services or materials; the date the contract is completed, abandoned or terminated; and the date a subcontract is certified complete under section 33.

Four events, earliest wins, and three of them are outside your control. That is why watching for publication of substantial performance is not optional in Ontario.

How you preserve it — section 34(1): where the lien attaches to the premises, "by the registration in the proper land registry office of a claim for lien on the title of the premises"; where it does not, "by giving to the owner a copy of the claim for lien." Where the owner is the Crown, the copy goes to the prescribed office or the ministry or Crown agency for whom the improvement is made (s. 34(3)); where the owner is a municipality, to the clerk of the municipality (s. 34(3.1)).

Stage two — perfection. Section 36(1): "A lien may not be perfected unless it is preserved." Section 36(2):

"A lien that has been preserved expires unless it is perfected prior to the end of the 90-day period next following the last day, under section 31, on which the lien could have been preserved."

Note the wording: 90 days from the last day the lien could have been preserved, not from the day you actually registered it. Registering on day 12 of the 60 does not buy you extra time at the far end.

Perfection means commencing an action to enforce the lien and, where the lien attaches to the premises, registering a certificate of action on title (s. 36(3)). The trust and prompt-payment machinery that sit alongside these lien deadlines in the same Act are covered separately: Ontario prompt payment: 28 days, 7 days, and a new invoice rule.

Alberta: 60 days, unless it is concrete or a wellsite

Alberta puts everything in one section. Section 41 of the Prompt Payment and Construction Lien Act sets the registration window for materials (subsection 1), for services (subsection 2) and for wages (subsection 3), and each of the three uses the same three-part structure:

"(a) subject to clauses (b) and (c), terminating 60 days from the day that the last of the materials is furnished or the contract to furnish the materials is abandoned, (b) with respect to improvements to an oil or gas well or to an oil or gas well site, terminating 90 days from [the same event], or (c) with respect to improvements primarily related to the furnishing of concrete as a material or work done in relation to concrete, terminating 90 days from [the same event]."

Two things to take from that.

The trigger is your own last day, not the project's. Alberta counts from the day you last furnished materials or completed services — a cleaner rule than Ontario's earliest-of-four, and one that a subcontractor can actually diarize on site.

The concrete exception is broader than it sounds. "Improvements primarily related to the furnishing of concrete as a material or work done in relation to concrete" reaches beyond ready-mix suppliers into forming, placing and finishing.

The holdback is in section 18(1): an owner liable on a contract under which a lien may arise "shall, when making payment on the contract, retain an amount equal to 10% of the value of the work actually done and materials actually furnished for a period of 60 days from" the issue of a certificate of substantial performance, or the date of completion of the contract where no certificate is issued. Subsections (1.1) and (1.2) extend that retention period to 90 days for oil and gas wells and well sites, and for concrete — matching the lien periods.

Section 18(2) adds that while a lien is registered, the owner must also retain any unpaid amount payable under the contract over and above the 10 percent. The payment and adjudication deadlines running under the same Act are covered separately: Alberta prompt payment: 28 days, 7 days, and a proper invoice.

British Columbia: 45 days, and someone else can start a 21-day clock

British Columbia is the shortest window of the three, and it is measured from the head contract rather than from your own work. The full mechanics — including how to force a certificate of completion — are in British Columbia builders lien: 45 days from the head contract.

Section 20(1): where a certificate of completion has been issued with respect to a contract or subcontract, the claims of lien of the contractor or subcontractor and of "any persons engaged by or under" them "may be filed no later than 45 days after the date on which the certificate of completion was issued."

Section 20(2), where no certificate has been issued, gives 45 days after:

"(a) the head contract has been completed, abandoned or terminated, if the owner engaged a head contractor, or (b) the improvement has been completed or abandoned, if paragraph (a) does not apply."

Read that carefully. Your own last day on site does not start the clock in British Columbia. A finishing trade that left the site in March may still be inside the window in September, and a sub who finished early may be relying on a head contract that has not completed. Both directions are counter-intuitive if you are used to Ontario or Alberta.

Enforcement — section 33(1): an action to enforce the claim of lien must be commenced, and a certificate of pending litigation registered, "not later than one year from the date of its filing".

A year sounds generous. It can be cut to three weeks. Under section 33(2) an owner, or a lien claimant who has commenced an action, may serve a notice to commence an action requiring the claimant to commence and register within 21 days after service of the notice. Service by mail is deemed effective "on the eighth day after deposit of the notice in the Canada Post Office at any place in Canada" (s. 33(4)).

And section 33(5) leaves nothing to interpretation: unless the action is commenced and the certificate registered in time, "the lien is extinguished."

Holdback: section 4(1) requires the person primarily liable on each contract and each subcontract to retain 10 percent of the greater of the value of the work or material actually provided, and the amount of any payment made on account of the contract price. Section 8 makes the holdback period 55 days — expiring 55 days after the certificate of completion is issued (s. 8(1)) or, where subsection (1) does not apply, 55 days after the head contract is completed, abandoned or terminated, or the improvement is completed or abandoned (s. 8(2)).

Forty-five days to file, fifty-five days of holdback. The ten-day gap is the point: it gives the payer a short window after the last liens could have been filed before the money is released.

Quebec is a different legal system, not a different number

Quebec does not have a construction lien. It is a civil law jurisdiction, and construction claims are secured by a legal hypothec under the Civil Code of Québec — a different instrument, registered in a different register, with its own conditions, its own notice requirements and its own deadlines.

We are not going to state those deadlines here, because we could not verify them against the official consolidated text at the time of writing. What matters for a contractor is the structural point: a Quebec job is not an Ontario job with different numbers. If you are working in Quebec, get the deadlines from the Civil Code of Québec and from a Quebec construction lawyer, not from a common-law lien guide. What Quebec does require on every invoice, instead of a lien calendar, is covered separately: Quebec RBQ licence: the number belongs on every invoice.

What to record on every job, in every province

The deadlines differ; the inputs do not. Four dates, recorded as they happen:

1. The date you started on site.
2. The date you last supplied services or materials — the Alberta trigger, and one of Ontario's four.
3. The date the head contract completed, was abandoned or was terminated — the British Columbia trigger.
4. The date a certificate or declaration of substantial performance was published or issued — the Ontario and Alberta trigger, and one you have to watch for rather than be told.

Most small contractors have none of these written down anywhere, which is why the usual conversation with a construction lawyer starts with "when did you actually finish?" and gets an approximate answer.

---

Current as of August 29, 2026. This article describes lien deadlines in Ontario, Alberta and British Columbia only, and is not legal advice. It does not cover Quebec's legal hypothec, the other provinces and territories, federal Crown land, the content and form requirements for a claim of lien, notice requirements, trust claims, or the consequences of an exaggerated or false claim — which are serious in every province discussed. Lien statutes are amended frequently: Ontario's Construction Act had provisions come into force on 1 January 2026. The e-Laws consolidation and the British Columbia and Alberta texts consulted were current on the dates published by those sources and were checked on the date shown. Consult a construction lawyer in the province where the land is situated.

What Zirko does: it holds jobs with their dates, documents and files in one place, so a start date, a last-work date and a completion date are recorded rather than reconstructed. Zirko does not track lien deadlines, does not warn you before one expires, does not prepare or register liens and gives no legal advice. Issued documents are immutable; a correction is a separate document, so the billing history of a disputed job survives intact.