Proper Invoice Requirements in Ontario
Under the Construction Act, R.S.O. 1990, c. C.30
A proper invoice is the single document that starts the Ontario payment clock under the Construction Act (R.S.O. 1990, c. C.30). Get it right and every downstream deadline is anchored and defensible; get it wrong and a payer can argue the clock never started.
In Ontario, if the payer does not flag a defect within 7 days (Ont. Construction Act s. 6.1(2)), the invoice is deemed a proper invoice and the payment clock runs from receipt.
Ontario proper invoice deadlines
The statutory clocks for this topic in Ontario, with section citations.
| Clock | Value | Statute |
|---|---|---|
Deemed-proper review window If the payer does not flag a defect in the invoice, it is deemed a proper invoice. Ont. Construction Act Section 6.1 | 7 days | Ont. Construction Act Section 6.1 |
What a proper invoice must contain
Ontario proper invoices identify the contractor and the payer, describe the work or materials supplied, state the amount payable and the period covered, give the contract or project reference, and set out the payment terms. Any additional content the contract requires must also be present.
Tiercord validates each invoice against these requirements in real time and generates a PDF whose footer carries a SHA-256 verification hash and QR code, so the recipient can confirm it has not been altered.
The 7-day deemed-proper window
Ontario is a deeming province. If the payer wants to reject an invoice as not proper, it has 7 days (Ont. Construction Act s. 6.1(2)) to say so. Stay silent past that window and the invoice is treated as proper, which starts the 28-day owner-payment clock whether or not anyone reviewed it.
Why the receipt date anchors every ON clock
Every Ontario prompt-payment deadline is measured from the date the proper invoice is received, not the date it is dated or sent. Recording and preserving that receipt date determines when the owner must pay and when every downstream clock expires.
Proper invoice in Ontario: FAQ
Does Ontario deem an invoice proper if the payer stays silent?
Yes. If the payer does not raise a defect within 7 days (Ont. Construction Act s. 6.1(2)), the invoice is deemed a proper invoice.
When does the payment clock start in Ontario?
On the date a proper invoice is received (Ont. Construction Act s. 6.4(1)). If the invoice is missing required information it may not qualify, and the clock may not start until the defect is cured.
See the full Ontario guide
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