Ontario’s prompt-payment rules say you must be paid within 28 days of a proper invoice. That sounds great. But the rule only matters if there’s a consequence when someone ignores it. That consequence is ODACC adjudication: a fast, low-cost process that produces a binding, court-enforceable decision in roughly 35 days.
Most Ontario contractors have never heard of it. This guide explains what ODACC is, when to use it, exactly how to file, and what to do once you have a determination in hand. It is written for trades contractors (electricians, plumbers, and HVAC techs), not lawyers. For a complete overview of the 28-day system these rules sit inside, see the Ontario Construction Act prompt payment guide.
What is ODACC and when can you use it
ODACC stands for Ontario Dispute Adjudication for Construction Contracts. It is the body created by the Ontario Construction Act to administer interim adjudication for construction payment disputes. “Interim” means the decision is binding right now, during the project, not at the end of a multi-year lawsuit.
ODACC maintains a registry of certified adjudicators, runs the online filing portal, and certifies the final determination so it can be filed in court. As of January 1, 2026, parties can also use a private adjudicator (qualified by ODACC but not from the public registry) if both sides agree and negotiate the fee directly.
You can refer a dispute to ODACC adjudication on any of the following matters under the Construction Act:
- The amount of a contractor’s or subcontractor’s invoice
- A disputed Notice of Non-Payment (Form 1.1)
- The amount of a holdback that is due
- A change order or change directive that is disputed
- Release of a lien in exchange for security
- Any other matter the parties agree in writing to refer
You cannot use adjudication to resolve a general negligence claim, a defect dispute unconnected to a payment obligation, or a matter already decided by a court. Adjudication is a payment-focused process, not a replacement for litigation.
When to file: the prompt-payment trigger
The most common trigger is a missed or disputed payment on a proper invoice. Here is the sequence that leads to an adjudication filing:
One important deadline: under the 2026 amendments, you have up to 90 days after completion, abandonment, or termination of the contract to initiate an adjudication. Do not wait too long after a project wraps or you may lose the right to file.
Fees: $0 under $50K, scaled above
ODACC charges two separate administrative fees. Both are $0 for disputes under $50,000. That is the part that surprises most contractors: you pay nothing to ODACC itself to start a small adjudication.
For disputes of $50,000 or more, ODACC charges:
- A Referral Fee of $600 plus HST, paid by the claimant only (not split). This is the fee to start the adjudication.
- A Certification Fee of $120 plus HST, split equally between the parties, paid when ODACC certifies the final determination.
Together that’s $720 + HST in ODACC fees on a claim of $50K or more, still inexpensive compared to construction litigation. Confirm the current schedule at odacc.ca/en/claimants/fees.
The adjudicator’s fee is separate and is agreed between you, the other party, and the adjudicator. If the parties cannot agree, ODACC sets the fee. ODACC also charges an administrative fee on the adjudicator’s fee: 50% where that fee is $3,000 or less, and 40% where it exceeds $3,000. These are still small numbers relative to the amount typically in dispute.
For a disputed invoice of $15,000, the realistic total cost is often under $2,000 in adjudicator fees, split between parties, with a $0 certification fee. Compare that to the retainer for a construction litigation lawyer.
Step-by-step filing process
1. Send written notice to the other party
Before filing with ODACC, you must notify the other party in writing that you intend to refer the dispute to adjudication. This is a mandatory first step under the Act. A text or email stating clearly “I am referring this dispute to ODACC adjudication” is sufficient, but email with a read receipt is better for your paper trail.
Include the invoice number, the amount in dispute, and a one-sentence description of the issue (“Payment not received 35 days after proper invoice dated March 3, 2026, for electrical work at 412 Lakeshore Rd.”). Keep it factual.
2. Submit a Notice of Adjudication to ODACC
Go to odacc.ca and create an account on ODACC’s online portal. The portal walks you through creating a Notice of Adjudication. You enter a brief description of the dispute and the amount (or other relief) you are seeking.
If you prefer not to use the online portal, you can fill in the form manually and file by email to support@odacc.ca or by fax to 416-362-8825. ODACC staff will help you if you get stuck: contact them at support@odacc.ca.
Once filed, ODACC appoints an adjudicator from its registry (or confirms a private adjudicator if both parties agreed on one).
3. Submit your documents within 5 days
Within 5 days of the adjudicator being appointed, you must submit your full document package to both the adjudicator and the respondent (the party you are claiming against). This is your one opportunity to put your evidence on the table. The package typically includes:
- The contract or subcontract
- The disputed invoice(s) with all backup (material receipts, time sheets, delivery records)
- Any correspondence about the dispute (emails, Form 1.1 if received)
- Photos of completed work, if relevant
- Any written arguments you want the adjudicator to consider
The respondent then has a set number of days (typically 5 days after receiving your documents) to submit their reply. The adjudicator may also request additional information from either party.
4. Adjudicator decision in 35 days
The adjudicator must issue a written determination within 30 days of the date you submitted your documents. ODACC then certifies the determination within 7 daysof receiving it. End to end, you typically have a binding decision within 35 days of submitting your documents, which is itself only a few days after the adjudicator is appointed.
The determination covers the amount owing, any interest, and who pays the adjudicator’s fees. It is binding on both parties immediately. The respondent must pay the amount ordered before they can challenge the decision through judicial review.
What documents you need
ODACC adjudication is evidence-based. The adjudicator reads what you give them. Strong documentation wins disputes; weak documentation loses them. Before you file, make sure you have:
| Document | Why it matters |
|---|---|
| Signed contract or subcontract | Establishes the scope, price, and payment terms that form the basis of your claim. |
| Proper invoice(s) with send timestamp | Starts the 28-day clock. Must meet the six proper-invoice fields or the adjudicator cannot award payment under the Act. |
| Proof of delivery (email, courier receipt, portal confirmation) | Proves when the clock started. An invoice you can't prove was received is an invoice with no clock. |
| Form 1.1 Notice of Non-Payment (if received) | Shows what, if anything, was disputed and whether the notice met the specificity requirements. |
| Material invoices and delivery tickets | Supports the amount claimed for materials. Adjudicators can and do reduce awards where amounts aren't backed up. |
| Site photos and inspection reports | Proves work was performed as invoiced. Date-stamped photos from a smartphone are acceptable. |
| Correspondence (emails, texts, letters) | Shows whether the other party acknowledged the work, the price, or the dispute verbally before going silent. |
Keep every document organized by project as you go, not after a dispute starts. By the time you need to file, it is too late to reconstruct a paper trail from memory.
Enforcing the determination
A certified ODACC determination is not just a piece of paper. It is enforceable as if it were an order of the Ontario Superior Court of Justice. Here is how enforcement works in practice:
- ODACC provides you with a certified copyof the determination through its online portal within 7 days of the determination being issued.
- Take that certified copy, plus two additional copies, to the Civil Intake Office of the Superior Court of Justice. File it there. The court stamps and certifies a copy for you.
- Give written notice of the filing to the other party within 10 days of filing with the court.
- The determination can now be enforced like any court order: writ of execution, garnishment of bank accounts, seizure of assets.
You have two years from the date of the determination (or from the outcome of any judicial review application) to file with the court. Do not wait. File promptly, especially if the other party is a smaller company with limited assets.
The respondent can apply for judicial review of the determination to the Divisional Court, but they need leave (permission) to do so. More importantly, they generally must pay the adjudicated amount before pursuing judicial review. That pay-now-argue-later structure is one of the most contractor-friendly features of the adjudication system.
When ODACC isn’t the right move
Adjudication is powerful, but it is not always the right tool. Consider these situations before filing:
- Your invoice is not a proper invoice. If your invoice is missing required fields (period of work, contract reference, HST number), an adjudicator cannot start the 28-day clock, and your claim may fail. Fix the invoice first, reissue it, and restart the process.
- The dispute is mostly about defect liability, not payment. ODACC handles payment disputes. If the owner says the work was done wrong and they want money back, that is a different legal process. A construction lawyer is the right starting point.
- The amount is very small. For disputes under $2,000, Small Claims Court (up to $50,000 in Ontario as of October 1, 2025) may be simpler and require less paperwork. Adjudication is proportionate to the size of the dispute.
- You have a strong ongoing relationship with the other party. Adjudication is adversarial. If you work with this GC on six projects a year and this is a one-time billing confusion, a direct conversation may preserve more than a formal filing.
- Your lien deadline is approaching.Adjudication does not extend your lien rights. If the lien deadline (60 days from last supply in Ontario) is close, preserve your lien first, then file for adjudication. Losing your lien right is permanent.
Pre-filing checklist
Run through this before you file. Each item is something an adjudicator will look for.
Invoice qualifies as a proper invoice
Contractor name and address, invoice date, contract reference, period of work, amount and basis, HST number and tax amount all present.
Invoice delivery is documented
You can prove when and how the invoice was delivered: email timestamp, portal record, or courier receipt.
28-day window has passed (or dispute is active)
Either payment is late or a Form 1.1 was issued and you want to challenge it.
Written notice sent to other party
You have notified them in writing that you are referring the dispute to adjudication.
Contract or subcontract in hand
You have a copy of the signed agreement. If it was verbal, document every term you can recall in writing before filing.
Supporting documents assembled
Material invoices, delivery tickets, site photos, inspection reports, relevant correspondence all organized and ready to submit within 5 days of adjudicator appointment.
90-day window is still open
The contract has not been completed, abandoned, or terminated more than 90 days ago.
Lien deadline is not imminent
If the lien deadline is within 2 weeks, register the lien first. Do not let it expire while waiting for adjudication.
ODACC adjudication is one of the most contractor-friendly tools in Ontario law. A $0 cert fee for disputes under $50K, a binding decision in roughly 35 days, and enforcement that works like a court order. Most contractors will never need to use it. But knowing it exists, and knowing how to use it, changes every payment negotiation you have from this point forward. The other side knows too.
For more on the underlying prompt-payment framework, read our guide on Ontario’s prompt-payment rules and the 2026 Construction Act amendments.
This article is for general information only and does not constitute legal advice. For advice specific to your situation, consult a construction lawyer licensed in Ontario.