Getting paid
Construction lien basics for Canadian subcontractors
A construction lien is the single strongest tool a subcontractor has for getting paid, and the easiest one to lose by missing a date. It is a claim you register against the property you worked on, so that the owner cannot cleanly sell or refinance until your bill is dealt with. It turns "please pay me" into "the title is encumbered until this is resolved," which is a very different conversation. The catch is that lien rights come with hard deadlines, and in every province those deadlines are short and unforgiving. Miss the window and the strongest tool you had is gone, no matter how right you are about the money.
We built SubTrade inside Quality Gypsum Services, a commercial drywall contractor in Calgary, Alberta, so we have lived on the sub side of this. This is a plain-language walk through the basics. It is general information, not legal advice, and lien law is provincial and detail-heavy, so treat the specific deadlines as a prompt to confirm the current statute or call a construction lawyer, not as the final word.
What a construction lien actually is
When you supply labour or materials that improve a property, most Canadian provinces give you a right to claim a lien against that property for the value of what you contributed. The lien attaches to the land and the improvement, and it sits on title as a registered claim.
Its power is leverage. An owner who wants to sell, refinance, or get a construction loan advanced usually cannot do so with liens sitting on title. That pressure is what moves a stalled payment. A lien does not by itself put money in your account, but it puts you in line, protects your priority against other creditors, and forces the dispute to get resolved rather than ignored.
The names differ by province. In British Columbia, Alberta, Saskatchewan, and Manitoba it is a builders' lien. In Ontario it is a construction lien under the Construction Act. Several Atlantic provinces still call it a mechanics' lien. In Quebec the equivalent is the legal hypothec of construction. The mechanics differ too, but the core idea is the same everywhere.
Who can file, and for what
Lien rights generally run to anyone who supplied work or materials to improve the property: subcontractors, sub-subcontractors, material suppliers, and often equipment or rental suppliers. You do not need a contract directly with the owner. A drywall sub hired by the general contractor still liens the owner's property, which is exactly what makes the right so useful down the contracting chain.
What you can claim is the unpaid value of the work and materials you actually provided to that project. A lien is tied to a specific improvement on a specific property, so you cannot roll an unpaid balance from one job onto a different owner's title. Keep your costs traceable to the job. If your labour and material records are not tied cleanly to the project, proving the lien amount gets harder than it should be, which is one more reason clean job costing is worth the discipline long before a dispute ever starts.
The two clocks that decide everything
Every provincial lien regime runs on two separate deadlines. Missing either one can end your claim.
The first is the deadline to register or preserve the lien: a fixed number of days, counted from your last day of work on the project or from a milestone like substantial completion, within which you must register the claim against title. This is the deadline subs blow most often, usually because they kept waiting for a payment that was never going to come voluntarily.
The second is the deadline to perfect the lien: after registering, you have a further limited period to start a court action and register a certificate of pending litigation, or the registered lien expires. Registering is not the finish line. It is the first of two steps, and the second one also has a clock.
Preservation deadlines vary by province
The registration window is where subcontractors get caught, because the number of days is different in every province and it is shorter than most people assume. These are commonly cited periods, but they change with legislation and depend on how completion is defined, so confirm the current act before you rely on any of them.
| Province | Lien name | Common registration window |
|---|---|---|
| British Columbia | Builders' lien | 45 days from completion, certification, or abandonment |
| Alberta | Builders' lien (Prompt Payment and Construction Lien Act) | 60 days from last work, longer for some concrete and oil and gas work |
| Saskatchewan | Builders' lien | 40 days from last work or substantial completion |
| Manitoba | Builders' lien | 40 days from last work or substantial completion |
| Ontario | Construction lien (Construction Act) | 60 days from substantial performance, completion, or abandonment |
| Quebec | Legal hypothec of construction | 30 days from end of work, with notice and publication requirements |
The Atlantic provinces run their own mechanics' lien acts with their own periods, commonly in the 30 to 60 day range. Alberta's rules sit inside the Prompt Payment and Construction Lien Act, and Ontario's inside the Construction Act. Both have been amended in recent years, which is exactly why a figure you remember from an old job may already be wrong.
How liens and holdback fit together
Holdback and liens are two halves of the same protection, and confusing them costs subs money. Holdback is the percentage every payer up the chain is required to hold back from what they pay, sitting in reserve so there is a fund available to satisfy lien claims. The lien is your claim against that property and, in practice, against that holdback fund.
The connection is the timing. The holdback is released a set period after substantial completion, and your lien registration window is tied to the same completion milestones. Register in time and you have a claim against a fund that is legally required to exist. Miss the window and the holdback gets released to everyone above you while you have no lien to claim against it. If you want to see roughly what should be sitting in that reserve on your job, our construction holdback calculator runs the provincial percentages, and the holdback by province guide walks through how each one works alongside progress billing.
How to protect your lien rights in practice
You do not need to file a lien on every job. You need to be ready to file on any job, which means the groundwork is done before there is ever a problem.
- Know your province's registration deadline and count it from the correct date, usually your last day of real work on that project, not the invoice date.
- Keep costs traceable to each job so the lien amount is provable, labour, materials, and equipment tied to the project.
- Track your last day of work per project, because that is where most deadline clocks start.
- Watch the aging on unpaid invoices and act well before the deadline, not on the last day.
- When a balance goes seriously past due and the deadline is approaching, talk to a construction lawyer before the window closes, not after.
Most of this is record-keeping you should be doing anyway. A live view of what each job has billed, what is outstanding, and when work last happened on site is the same information that protects a lien claim, which is part of what our construction management features are built to keep in one place. SubTrade starts at $299/month CAD with a 14-day free trial and no credit card required.
FAQ
What is a construction lien in Canada?
A construction lien, called a builders' lien or mechanics' lien in some provinces, is a registered claim against the property you improved with your labour or materials. It encumbers the property's title so the owner cannot cleanly sell or refinance until your unpaid balance is resolved, which gives subcontractors real leverage to get paid.
Do I need a contract with the owner to file a lien?
No. Lien rights generally flow to anyone who supplied work or materials to improve the property, including subcontractors and suppliers who were hired by the general contractor and have no direct contract with the owner. That is what makes the lien so valuable down the contracting chain.
How long do I have to file a construction lien?
It depends on the province and is usually short, commonly 30 to 60 days from your last day of work or from substantial completion. British Columbia is 45 days, Ontario and Alberta are 60, Saskatchewan and Manitoba are 40, and Quebec is 30. Always confirm the current statute, because the periods and the trigger dates change.
What is the difference between registering a lien and perfecting it?
Registering, or preserving, the lien puts your claim on title within the first deadline. Perfecting it means starting a court action within a second deadline so the lien does not expire. Both steps have their own clocks, and registering alone does not keep the lien alive indefinitely.
How is a lien different from holdback?
Holdback is the percentage every payer is required to hold back to create a reserve fund. The lien is your claim against the property and, in effect, against that fund. Holdback creates the money; the lien is how you reach it if you are not paid, and the two deadlines are linked to the same completion milestones.
Should I file a lien or just keep asking for payment?
Keep the option open by tracking the deadline from the start, and use the lien as leverage when a balance goes seriously past due and normal collection has stalled. Because the deadline is short and final, the mistake is waiting too long, not acting too soon. When it gets close, get legal advice before the window closes.
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