← Back to Blog

Disputing Fault in Ontario Car Accidents – A Self-Help Guide

By SelfRepSupport Team — support@self-represented-help.ca
Ontario | Car crash fault fights, insurance disputes, first court dates
Your goal: Make the insurance company follow Ontario’s official Fault Determination Rules (Ontario Regulation 668). Not “their opinion,” not “the other driver’s story.” The law. If they blamed you unfairly, you’re allowed to challenge it.

When you should dispute

Fight the fault decision if any of these sound like you:

Once the insurer decides the crash is “your fault,” that sits on your record. Your premiums go up for years. So don’t just accept it if it’s wrong.

Your job in plain English

You’re not writing a novel. You’re doing 3 things:

Example:
“You said I’m 50% at fault for a rear-end. I was fully stopped at a red light. The other car hit me from behind. Under the Fault Determination Rules, rear-end collisions are generally assigned to the driver who strikes from behind. Please correct my fault rating.”

Step 1. Get the paperwork

Ask (in writing) for all of this:

Keep everything in writing. Email is fine. You want a trail you can forward later.

Say this in your email:
“Please provide the section(s) of Ontario Regulation 668 (Fault Determination Rules) that you relied on to find me at fault, and a copy of the collision diagram / notes you’re using. I am formally disputing your assessment.”

Step 2. Compare their version to what really happened

Now you’re looking for mismatch. Insurance companies are fast, and “fast” = “lazy copy/paste sometimes.”

Ask yourself:

If their write-up is wrong, don’t panic. That’s common. You just calmly correct it and tie it back to the real rule that applies.

Step 3. Write back and point to the right rule

Your dispute email should be short and clinical. You’re not begging. You’re showing them: “You applied the wrong rule.”

Use this structure:

Important: Don’t apologize. Don’t self-blame. Don’t say “I’m not an expert but…” You’re just calmly pointing at the law they are supposed to follow anyway.

Step 4. Ask for confirmation in writing

Ask them to confirm (in writing) that they’ve updated your fault % in their system. You want that because if you switch insurance later, the new company will ask “Any at-fault accidents?” and this is how you prove “Nope.”

If they refuse to fix it or they go quiet, don’t freak out. You now have a written dispute trail. That’s evidence. That can go to escalation.

Will this hurt my claim?

No. You’re literally using their own rules. Insurers expect people to dispute fault. They may not love it, but it’s normal.

This is not “suing them.” This is “please apply Ontario Regulation 668 correctly.” That’s boring compliance stuff, not drama.

When you should get help right now

You're allowed to get help BEFORE you say something that can be twisted. Insurance adjusters do this every day. You don't. So protect yourself.

Need help fixing a bad fault decision? Click below. We’ll review your insurer’s letter and tell you what to say back.

Need help? Click here →