In short
It could be a contractor who wasn't paid, the CRA or a lender.
Liens usually have to be paid off and discharged before the property can be sold or refinanced cleanly.
How liens work in Ontario
A lien is a claim registered against a property because the owner, or someone who worked on the property, is owed money. It shows up on the property's parcel register, so anyone searching title can see it.
Common examples include a mortgage, an unpaid contractor's construction lien, a court judgment registered as an execution, and tax debts owed to the government. Unpaid property taxes can also become a priority claim against the property itself.
Most liens need to be paid and formally discharged from title before the property can be sold or refinanced cleanly.
A lien doesn't change who owns the property. It means the creditor has a legal claim that must be dealt with, usually by paying the debt, before the owner can transfer clean title to a buyer or put a new mortgage in place.
Construction liens and the 10% holdback
Under Ontario's Construction Act, contractors, subcontractors and suppliers who aren't paid can register a lien against the property they improved. That includes renovations on a house.
Deadlines are tight. In general, a lien must be preserved (registered) within 60 days of the job being completed or abandoned, and then perfected, by starting a court action and registering a certificate of action, within a further 90 days. If it isn't, it expires.
The Act also requires owners and contractors to hold back 10% of each payment as a holdback until the lien period ends. That holdback protects you if your contractor doesn't pay their subcontractors.
What it means when you buy or sell
When you buy, your lawyer searches title and executions, and arranges for any liens to be paid from the seller's sale proceeds and discharged on or after closing.
When you sell, your lawyer will need to deal with any liens on title before closing. If you've had recent renovations, keep your invoices and proof of payment handy.
If a lien turns up that you don't recognize, don't ignore it. A lien that's properly preserved can lead to a court action against the property, so talk to a lawyer about your options, which may include paying money into court to have it removed from title while the dispute is sorted out.
Common questions about lien
Can you sell a house with a lien on it in Ontario?
Yes, you can sell a house with a lien, but the lien usually has to be paid out of the sale proceeds and discharged from title. Buyers and their lenders expect clear title on closing. Your lawyer arranges the payout and the discharge as part of the closing.
How long does a contractor have to file a lien in Ontario?
In general, a contractor has 60 days after the work is completed or abandoned to register a construction lien in Ontario. The lien then has to be perfected, by starting a court action and registering a certificate of action, within another 90 days or it expires. The exact start date depends on the contract, so confirm with a lawyer.
What is the 10% holdback in Ontario?
The holdback is 10% of the value of work done that an owner or contractor keeps back under Ontario's Construction Act. It's released after the lien period ends if no liens are registered. It protects owners when a contractor doesn't pay subcontractors or suppliers.
How do I find out if there is a lien on a property?
Search the property's parcel register through ONLAND, Ontario's online land registry, or ask a real estate lawyer. Registered liens, mortgages and certificates of action appear on the register. On a purchase, your lawyer does this search, along with execution and tax searches, before closing.
Sources
General information for Ontario, updated October 2026. Not legal, tax or mortgage advice. Rules change, so confirm with your lawyer, lender or the source above before you rely on it.