How long does the owner have to reject an invoice?

Receive any written notice that an invoice is deficient within 7 days after the owner receives it, or the invoice is deemed a proper invoice (s 6.1(2), 6.3(6)). In force from 1 January 2026. The owner's notice must say what is deficient and what is required to address it; without one in time, the invoice is deemed proper for Part I.1 and the 28 day payment and 14 day non-payment clocks run.

When is a notice of non-payment due?

Receive any notice of non-payment within 14 days after the owner receives a proper invoice, or the full amount is payable by day 28 (s 6.4(2), (3), 6.7; O. Reg. 303/18 s 3(a); O. Reg. 304/18 s 4). The owner may withhold only the amount a notice of non-payment specifies, and the notice must be in Form 1.1 (paper or electronic) and detail all of the reasons; every other amount stays due within 28 days (s 6.4(1), (3)).

When must a contractor pay its subcontractors?

Pay each subcontractor whose work was in a proper invoice within 7 days after receiving the owner's payment of it (s 6.5(1)-(3), 6.6(1)-(3), (11)). Pay each subcontractor within 35 days after giving the owner the proper invoice, even if the owner has not paid, unless a notice of non-payment is given (s 6.5(4), 6.6(4), (5), (10)).

Is interest payable on a late payment?

Charge interest on any amount not paid when the Act makes it due, at the prejudgment interest rate or the contract rate if higher (s 6.9, 13.19(3), (4)). Interest begins to accrue on the due date, at the prejudgment interest rate under the Courts of Justice Act s 127(2) or, if the contract or subcontract specifies a different rate, the greater of the two (s 6.9).

Do these rules apply to my contract?

Parts I.1 (prompt payment) and II.1 (adjudication) do not apply to a contract entered into before 1 October 2019, to a later contract whose procurement the owner commenced before that day, or to a subcontract under either (s 87.3(4)). A contract entered into, or procured, before 1 July 2018 stays under the Act as it read on 29 June 2018 (s 87.3(1)).

Ontario / Construction Act / Prompt payment

How does prompt payment work under Ontario's Construction Act?

In Ontario the owner pays every undisputed amount of a proper invoice within 28 days of receiving it. It has 7 days to say it is deficient and 14 days to give a notice of non-payment. The contractor pays its subcontractors within 7 days of being paid, or within 35 days of invoicing if the owner has not paid.

From proper invoice to payment

Every clock runs from the day the owner receives the proper invoice. The owner has 7 days to give a deficiency notice and 14 days to give a notice of non-payment; every amount it does not dispute is due within 28 days. The contractor then has 7 days from being paid to pay its subcontractors, and each subcontractor the same 7 days towards its own. Calendar days: the Act defines no business day.

Duty	Window and section	If missed
Determine which version of the Act, and whether its prompt payment and adjudication Parts, govern the contract	none sets 1(4), 4, 5(1), 87.3(1), (4), 87.4; O. Reg. 304/18 s 13	no penalty statedDisputes
Give the owner a proper invoice every month, unless the contract sets another cadence	1 months 6.3(1)-(4)	no penalty statedDisputes
Make every invoice to the owner a proper invoice: contractor's name and address, date and period or milestone, the contract reference, a description of what was supplied, the amount and payment terms, and who is to be paid	none sets 6.1(1), 6.3(5), (6)	the claim is barredDisputes
Receive any written notice that an invoice is deficient within 7 days after the owner receives it, or the invoice is deemed a proper invoice	7 dayss 6.1(2), 6.3(6)	no penalty statedDisputes
Receive any notice of non-payment within 14 days after the owner receives a proper invoice, or the full amount is payable by day 28	14 dayss 6.4(2), (3), 6.7; O. Reg. 303/18 s 3(a); O. Reg. 304/18 s 4	you are liable for the full amountDisputes
Be paid every amount of a proper invoice that no notice of non-payment disputes within 28 days after the owner receives it	28 dayss 6.2, 6.4(1), (3)	no penalty statedDisputes
Pay each subcontractor whose work was in a proper invoice within 7 days after receiving the owner's payment of it	7 dayss 6.5(1)-(3), 6.6(1)-(3), (11)	a breach of contractDisputes
Pay each subcontractor within 35 days after giving the owner the proper invoice, even if the owner has not paid, unless a notice of non-payment is given	35 dayss 6.5(4), 6.6(4), (5), (10)	a breach of contractDisputes
Give a subcontractor any notice of non-payment within 7 days after receiving the owner's notice of non-payment, or before day 35 after the invoice if the owner gave none	7 dayss 6.5(5)-(8), 6.6(6)-(9); O. Reg. 303/18 s 3(b)-(e); O. Reg. 304/18 s 4	you are liable for the full amountDisputes
Charge interest on any amount not paid when the Act makes it due, at the prejudgment interest rate or the contract rate if higher	none sets 6.9, 13.19(3), (4)	no penalty statedDisputes

What the library notes on each duty

Quoted a whole sentence at a time from the library's note on each row.

Determine which version of the Act, and whether its prompt payment and adjudication Parts, govern the contract

s 1(4), 4, 5(1), 87.3(1), (4), 87.4; O. Reg. 304/18 s 13 · none set · no penalty stated

Parts I.1 (prompt payment) and II.1 (adjudication) do not apply to a contract entered into before 1 October 2019, to a later contract whose procurement the owner commenced before that day, or to a subcontract under either (s 87.3(4)).
A procurement commences at the earliest request for qualifications, request for quotation, request for proposals or call for tenders (s 1(4)).
A contract entered into, or procured, before 1 July 2018 stays under the Act as it read on 29 June 2018 (s 87.3(1)).
The amendments in force on 1 January 2026 (Building Ontario For You Act (Budget Measures), 2024, Sched. 4) apply to every other improvement from that day (s 87.4(2)), except as s 87.4(3) to (7) provide: the annual holdback release starts later for a contract entered into before that day (s 87.4(4)).
Parts I.1 and II.1 do not apply to a Class I nuclear facility (O. Reg. 304/18 s 13), and apply with modifications to an alternative financing and procurement project agreement (s 1.1).
An agreement that the Act does not apply is void (s 4), and every contract and subcontract is deemed amended to conform (s 5(1)).

Give the owner a proper invoice every month, unless the contract sets another cadence

s 6.3(1)-(4) · 1 month · no penalty stated

Monthly unless the contract provides otherwise (s 6.3(1)).
A term that makes giving a proper invoice conditional on a payment certifier's prior certification or the owner's prior approval is of no force or effect (s 6.3(2)); certification or approval after the invoice is given, and testing and commissioning terms, are allowed (s 6.3(3), (4)).
No consequence is stated for the cadence itself.

Make every invoice to the owner a proper invoice: contractor's name and address, date and period or milestone, the contract reference, a description of what was supplied, the amount and payment terms, and who is to be paid

s 6.1(1), 6.3(5), (6) · none set · the claim is barred

Also any information the owner reasonably requests for its accounts payable system, any other requirement the contract specifies, and anything prescribed (s 6.1(1) para 6.1, 7).
Once given, a proper invoice may be revised only with the owner's advance agreement and without changing its date (s 6.3(5)).

Receive any written notice that an invoice is deficient within 7 days after the owner receives it, or the invoice is deemed a proper invoice

s 6.1(2), 6.3(6) · 7 days · no penalty stated

In force from 1 January 2026.
The owner's notice must say what is deficient and what is required to address it; without one in time, the invoice is deemed proper for Part I.1 and the 28 day payment and 14 day non-payment clocks run.
Applies the same way to a revised invoice (s 6.3(6)).
The clock runs from the owner's receipt; a document sent by certified or registered mail is deemed received on the fifth day after mailing, excluding Saturdays and holidays (s 87(2)).
Calendar days: the Act defines no business day.

Receive any notice of non-payment within 14 days after the owner receives a proper invoice, or the full amount is payable by day 28

s 6.4(2), (3), 6.7; O. Reg. 303/18 s 3(a); O. Reg. 304/18 s 4 · 14 days · you are liable for the full amount

Ontario's equivalent of a payment schedule.
The owner may withhold only the amount a notice of non-payment specifies, and the notice must be in Form 1.1 (paper or electronic) and detail all of the reasons; every other amount stays due within 28 days (s 6.4(1), (3)).
Reasons may include set-off under s 12 or s 17(3) (s 6.7).

Be paid every amount of a proper invoice that no notice of non-payment disputes within 28 days after the owner receives it

s 6.2, 6.4(1), (3) · 28 days · no penalty stated

Subject to the 10% holdback (s 6.2).
Calendar days: the Act defines no business day.
'No later than N days after' an event excludes the day of the event (Legislation Act, 2006 s 89(5)), and a time limit ending on a holiday runs to the next day that is not one (s 89(1)); Sunday is a holiday there, Saturday is not.

Pay each subcontractor whose work was in a proper invoice within 7 days after receiving the owner's payment of it

s 6.5(1)-(3), 6.6(1)-(3), (11) · 7 days · a breach of contract

Applies to full and partial payment; a partial payment is shared rateably, with any amount the owner withheld for a particular subcontractor's work held back from that subcontractor only (s 6.5(3)).
The same 7 days bind each subcontractor towards its own subcontractors (s 6.6).
The Act states no offence: a late payment carries interest (s 6.9) and can be adjudicated (O. Reg. 264/25 s 19(1)).

Pay each subcontractor within 35 days after giving the owner the proper invoice, even if the owner has not paid, unless a notice of non-payment is given

s 6.5(4), 6.6(4), (5), (10) · 35 days · a breach of contract

Applies to the amount the owner did not pay within 28 days, to the extent the subcontractor was not paid under s 6.5(2).
A subcontractor paying its own subcontractor has 7 days after it is paid or, if it is not paid, 42 days after the proper invoice was given to the owner (s 6.6(5)), and may ask the contractor to confirm that date, which the contractor must give as soon as possible (s 6.6(10)).
The Act states no offence.

Give a subcontractor any notice of non-payment within 7 days after receiving the owner's notice of non-payment, or before day 35 after the invoice if the owner gave none

s 6.5(5)-(8), 6.6(6)-(9); O. Reg. 303/18 s 3(b)-(e); O. Reg. 304/18 s 4 · 7 days · you are liable for the full amount

Where the owner has not paid: Form 1.2, stating the amount not paid because of the owner's non-payment, with a copy of any owner's notice and an undertaking to refer the matter to adjudication within 21 days (s 6.5(5)).
Where the contractor disputes the subcontractor's entitlement: Form 1.3, specifying the amount and detailing all of the reasons (s 6.5(6)).
Without a notice in time, the contractor must pay within the 7 or 35 days.
A subcontractor's notice to its own subcontractor is Form 1.4 or 1.5 on the same timing (s 6.6(6)-(8)).
Once the owner pays an amount covered by a Form 1.2 notice, the 7 day payment rule applies to it (s 6.5(8)).

Charge interest on any amount not paid when the Act makes it due, at the prejudgment interest rate or the contract rate if higher

s 6.9, 13.19(3), (4) · none set · no penalty stated

Interest begins to accrue on the due date, at the prejudgment interest rate under the Courts of Justice Act s 127(2) or, if the contract or subcontract specifies a different rate, the greater of the two (s 6.9).
The same rule applies to an amount an adjudicator determines (s 13.19(3)), without compounding on interest already under s 6.9 (s 13.19(4)).
The rate itself is set under the Courts of Justice Act and is not recorded here.

If the invoice is not paid

An unpaid amount can go to adjudication, and an unpaid party can preserve a lien. Every payment is subject to the holdback.

What this page is, and is not

It is the section text this library holds for Ontario's Construction Act, R.S.O. 1990, c. C.30 (Ontario), the Occupational Health and Safety Act, R.S.O. 1990, c. O.1 (Ontario) and Construction Projects, O. Reg. 213/91 (Ontario), with the window and the consequence. It is not legal advice, and it is not a substitute for reading the Acts, the regulations and the contract you signed.

Demiton does not yet track Ontario projects. These pages set out the duties; the product does not run these checks on an Ontario job today.

No library of law is complete, and Demiton never says this one is. An obligation the library does not hold, and you did not add, is not protected. You can add your own to any job.

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