# Is Your Invoice a "Proper Invoice"? Navigating Ontario's Prompt Payment Laws to Protect Your Cash Flow [Back to blog](https://bluecraneworks.ca/articles.html) Cash Flow Protection # Is Your Invoice a "Proper Invoice"? Navigating Ontario's Prompt Payment Laws to Protect Your Cash Flow Published: May 22, 2026 · Blue Crane™ · Hamilton, Ontario · 6 min read In the Ontario construction industry, cash flow is the lifeblood of the operation. Ontario's **Construction Act** includes prompt payment rules built to stop contractors and subcontractors from waiting months to get paid. The catch is simple: the statutory clock only starts once you submit a legally compliant **proper invoice**. ![Stock image of a contractor reviewing invoice paperwork in Hamilton, Ontario](https://images.unsplash.com/photo-1554224155-6726b3ff858f?auto=format&fit=crop&w=1600&q=80) Illustrative stock image for Hamilton, Ontario contractor billing, invoice review, and prompt payment documentation. If an invoice is missing required information, the paying party has an opening to challenge it and disrupt the payment timeline. That makes billing quality a field issue, not just an office issue. This article walks through the core Ontario Construction Act prompt payment timeline, the proper invoice requirements Ontario contractors need to satisfy, and how ODACC adjudication can help if the money still does not move. This is general information, not legal advice for a specific dispute. ## 1. The strict timelines: the 7, 28, and 14-day rules Once a valid proper invoice is delivered, the law starts a chain of short timelines that matter to every contractor payment dispute in Ontario. ### The 28-day owner payment rule The owner must pay the contractor within 28 calendar days after receiving the proper invoice, unless a valid notice of non-payment is delivered within the statutory framework. ### The 7-day dispute window If the owner says the invoice is deficient, they cannot sit on that point indefinitely. Under the updated regulations, they must raise that deficiency in writing within 7 days of receipt and identify what is missing. Miss that window and the invoice is treated as proper for prompt payment timing purposes. ### The 14-day subcontractor flow After the contractor receives payment from the owner, they generally have 14 calendar days to push the money down to subcontractors. The system is designed to keep cash flowing through the whole construction pyramid, not trapped at the top. What matters operationally Your invoice issue is not minor admin cleanup. If your paperwork fails the proper invoice test, the payment clock may never start cleanly. That is why a contractor payment timelines law problem often begins as a documentation problem. ## 2. The legal checklist: what makes an invoice proper? You cannot rely on a loose invoice template Ontario contractors have passed around for years. Section 6.1 of the Construction Act sets out what a proper invoice must include. 1. **The contractor's name and business address.** 2. The invoice date and the period when the services or materials were supplied. 3. **Information identifying the authority for the work.** That usually means the contract, purchase order, or agreement the invoice is tied to. 4. A description of the services or materials supplied, including quantities where applicable. 5. The amount requested for payment and the payment terms. 6. The name, title, mailing address, and telephone number of the person or office to whom payment is to be sent. 7. **Any additional information the contract requires** so long as it is not inconsistent with the Act, such as project codes or accounts-payable routing fields. The practical failure point Most invoice breakdowns happen because the work description is vague, the contract reference is missing, or the owner-specific routing field gets skipped. That is enough to create friction right when you need the 28-day clock running. ## 3. What happens if they still refuse to pay? If you delivered a compliant invoice, the deficiency window has passed, and payment is still late, Ontario gives you a fast-track path that is much faster than dragging a mid-project cash flow problem through ordinary litigation. The ODACC construction adjudication system exists for exactly this problem. A certified adjudicator reviews the contract documents, invoice records, notices, and payment history, then issues an interim binding decision meant to keep the project moving. ### Speed Adjudication is built for weeks, not years. That matters when payroll, material purchases, and supplier pressure do not stop just because someone upstream is slow-paying. ### Enforcement Once the adjudicator rules payment is owing, the paying party generally has 15 days to release the funds. That is a serious tool compared with waiting on a traditional lawsuit. ## 4. Lock in your billing infrastructure before the dispute starts Administrative sloppiness costs real money. If every project manager uses a different invoice layout, if supporting records are buried in email, or if the office has to rebuild the contract trail every month, you are handing the other side room to stall. The better approach is a standardized billing system that produces the same legally complete structure every time: contract reference, billing period, scope summary, amount, routing details, and supporting documentation kept together in one operational record. That does not guarantee a dispute will never happen, but it removes the easiest excuse for delaying payment and gives you much stronger footing if adjudication becomes necessary. Operational takeaway When your invoice system is consistent, searchable, and export-ready, you protect cash flow before the argument starts. That is the real value of clean documentation infrastructure. ## Quick answers contractors search for ### Does the 28-day clock start on every invoice? No. It starts when the invoice qualifies as a proper invoice under the Construction Act and is delivered in the required way. ### Can an owner reject an invoice weeks later? Not cleanly. The updated rules require a written objection within 7 days if the invoice is said to be deficient. ### What if the dispute is still holding up cash flow? That is where fast-track adjudication through ODACC becomes relevant for contractors trying to get paid mid-project. ## Related Ontario contractor reads ### Ministry of Labour inspection checklist red flags Use this when you want to tighten up field compliance records, AED proof, washroom logs, and Working at Heights documentation before an inspection lands on site. ### Ontario pre-qualification and compliance gatekeeping For contractors chasing bigger bids, this breaks down how organized safety and compliance documentation helps clear EllisDon, PCL, Avetta, and ISNetworld requirements. ### Browse the full Blue Crane contractor blog Use the blog hub to move between cash flow, inspections, and compliance topics that bring in colder search traffic from Ontario contractors and field-service businesses. Build the admin system before it hurts ## Get your invoices, records, and support files out of the spreadsheet pile Blue Crane helps contractors keep job paperwork organized, searchable, and ready when a client, accountant, or adjudicator needs proof fast. Try the demo ## Next, from Blue Crane - [**Proper invoice generator**Get the invoice right so the clock actually starts](https://bluecraneworks.ca/ontario-proper-invoice-generator.html) - [**Form 1.2 notice of non-payment**What to send when the money does not arrive](https://bluecraneworks.ca/ontario-form-1-2-notice-of-non-payment-generator.html) - [**Document Control Systems**Sign-offs, certs and safety records, provable in under a minute](https://bluecraneworks.ca/solutions/document-control.html) --- Source: https://bluecraneworks.ca/articles/ontario-construction-act-proper-invoice-prompt-payment