Auto Repair Estimate Laws in Ontario: Written Estimates, the 10% Limit and Invoices

Short answer: Under Ontario’s auto repair estimate laws, you must give a customer a written estimate before you charge for repair work, unless the customer sets a maximum price they will pay. The final invoice cannot be more than 10% above that estimate. After the job, you must hand over an itemized written invoice. These rules come from the Ontario guide for auto repair businesses.

That is the whole skeleton. The rest of this page is the detail a service writer needs on a Tuesday morning with three cars waiting: what goes on the estimate, how to record approval, what the invoice must show, and what to do when a customer pushes back.

Do the estimate rules differ between Toronto, Mississauga, Brampton and Ottawa?

Auto repair estimates and invoices in Ontario fall under the Consumer Protection Act, 2002, which is provincial law. A shop in Toronto, Mississauga, Brampton, Markham, Vaughan or Ottawa follows the same rules. That is why this is one page, not six near-identical city pages.

What does vary by city is outside this article: business licensing, zoning, signage and waste bylaws. Check those with your municipality.

What do Ontario’s auto repair estimate laws require, step by step?

1. Write the estimate before you charge

The Ontario guide says you must provide a written estimate of costs before you can charge for any work or repairs, except in certain cases. The main exception: the customer specifies a maximum amount they will pay, and your actual costs do not exceed it.

According to the guide, the estimate must include:

• Customer name and vehicle details (make, model, VIN, odometer reading; licence plate is good practice)
• Your business name, address and contact information
• An exact description of the proposed work
• Each part listed individually, noting whether it is new, used or reconditioned
• Each part’s price, plus total labour cost and how it is calculated
• Itemized charges for anything that is not parts or labour, such as storage
• The total, with the disclosure that the final cost cannot exceed the estimate by more than 10 per cent
• How long the estimate is valid and when the work will be completed

2. Get and record the customer’s authorization

Before you charge for work you need the customer’s authorization. Per the guide, if the authorization is not in writing, record the authorizer’s name, contact information, date and time, plus the phone number if it was given verbally. Recording the same details for written approvals is a sensible habit.

The practical point: “they said OK on the phone” is not a record. A name, a time and a number is.

3. What if the work goes beyond the estimate?

The Ontario guide page does not spell out a procedure for work that goes beyond the original estimate, so read the regulation text on e-Laws (Consumer Protection Act, 2002, and Ontario Regulation 17/05, which the guide names as the rules for auto repair businesses) or ask the ministry before you rely on any shortcut. As a shop practice, and not as a quote from the law, the safe approach is:

1. Stop work on the new item.
2. Tell the customer what you found and what it costs.
3. Record a fresh authorization with name, date and time.
4. Update the estimate so the paper matches reality.

4. How does the 10% limit work?

The guide is direct: the final invoice cannot be more than 10% higher than the written estimate. The mandatory invoice statement repeats it: a repairer may not charge an amount more than ten per cent above the estimate.

For example, assuming an estimate of $1,000 before tax: the most you could invoice is $1,100 before tax. If the job truly needs $1,350, the extra $250 needs its own authorization and a revised estimate, not a surprise at the counter. (Whether tax sits inside or outside the 10% test is something to confirm against the regulation or with the ministry; this example is illustrative only.)

Can an Ontario shop charge for an estimate?

An estimate fee is allowed if you disclose it in advance. The guide says it must cover diagnosis time, reassembly and any parts damaged during examination, and you cannot charge it when the customer authorizes the work.

What must an Ontario repair invoice show, and what warranty applies?

When the work is done, the guide says you must provide a written invoice that includes:

• All customer, vehicle and business information, with both the drop-off and return odometer readings
• The dates work was authorized and completed, and the date the vehicle was returned
• An exact description of the repair and the parts installed, with their condition (new, used, reconditioned)
• Each part’s price, shop supplies, and labour costs with the calculation method
• Itemized additional charges
• The total amount and payment method
• The estimate total, or the maximum amount the customer authorized
• Warranty terms
• The mandatory Consumer Protection Act statement

Returning replaced parts

You must offer to return removed parts unless the customer declined in writing, there is no charge to the customer for the repair or replacement, or a manufacturer’s warranty requires the part to go back to the distributor or manufacturer.

Warranty

The guide states that the mandatory warranty covers all new or reconditioned parts installed and the labour to install them, for a minimum of 90 days or 5,000 kilometres, whichever comes first. Exemptions listed include fluids, filters, lights, tires and batteries, among others. If a covered breakdown occurs, the repair is free.

How long to keep records

The Ontario guide says only that you should maintain a record of the initial estimate and gives no retention period on that page. Confirm the retention requirement in the regulation before you set a policy. Until then, keeping estimates, authorization notes and invoices together, per job, for as long as a customer could dispute the work is the conservative choice.

How does a Safety Standards Certificate relate to repair estimates?

A Safety Standards Certificate confirms a vehicle met minimum safety standards on the inspection date. Per Ontario.ca, it is not a warranty or guarantee of the vehicle’s condition, it is issued by Ministry of Transportation-licensed Vehicle Inspection Centres in the DriveON network after a vehicle passes, and it is valid for 36 calendar days from the inspection date. Fees are set by the station.

The link to estimates: if your shop is licensed to inspect, the certificate is separate from repair authorization. A failed inspection does not authorize repairs. The customer still needs a written estimate and still has to approve the work.

What HST applies to parts and labour in Ontario?

Ontario’s HST rate is 13%, according to the CRA’s which rate to charge page (re-read October 31, 2026; the page confirms 13% for Ontario and points to a separate place-of-supply page for the full rate table). The CRA’s GST/HST for businesses page covers registration, charging and remitting. Show tax as its own line on the estimate and the invoice so the customer can see what is parts, labour and tax.

For example, assuming $800 of parts and labour: HST at 13% is $104, for a total of $904.

Copyable Ontario estimate checklist

Copy this into your shop’s estimate template.

Header

• Customer name, phone, email
• Make, model, VIN, plate, odometer in
• Shop name, address, phone

Work and price

• Exact description of each repair
• Each part listed with new/used/reconditioned and price
• Labour total and how it is calculated (hours x rate)
• Other charges itemized
• HST shown as a separate line
• Total, with: “The final cost cannot exceed this estimate by more than 10 per cent”
• Estimate valid until (date), work completed by (date)
• Estimate fee, if any, disclosed

Authorization

• Authorizer’s name and contact
• Date and time
• Phone number if verbal
• Customer’s choice on returning replaced parts

At pickup

• Odometer out, completion date, return date
• Invoice matches the estimate within 10%
• Warranty terms and required Consumer Protection Act statement included

When a customer disputes the bill

1. Pull the estimate, the authorization record and the invoice for that job.
2. Compare the invoice to the estimate. If it is more than 10% over, the guide says the repairer may not charge the excess, so adjust it.
3. If there is no recorded authorization for a line item, expect to lose that argument.
4. If it is not resolved, the customer can complain to the ministry. The guide lists the Ministry of Public and Business Service Delivery and Procurement at 416-326-8800 or 1-800-889-9768, and CPOBusinessEducation@Ontario.ca for business questions.

The stakes are real. The guide lists consequences including an unenforceable agreement, a customer’s right to cancel within one year, listing on the Consumer Beware List, and, on conviction, fines up to $50,000 and/or imprisonment of up to two years for individuals and up to $250,000 for corporations, per the guide. The guide says businesses stay on the Consumer Beware List for 21 to 27 months after enforcement action. For unpaid work, the guide points to the Repair and Storage Liens Act. AARO is an Ontario aftermarket industry association; check its site for what support it offers members.

Can shop management software help with Ontario estimate rules?

Any shop system should do three things for this problem:

1. Keep an estimate record that cannot be quietly overwritten, with each part and labour line itemized.
2. Timestamp the approval, with who approved, by what channel and when.
3. Produce an itemized invoice that carries the estimate total next to the final total, so a 10% gap is visible before the customer sees it.

Mecano Shop covers estimates, inspections and texting as part of its shop management board, as described on the home page. That is a description of the product, not a statement that using it makes a shop compliant. You are responsible for the content of your estimates and invoices whatever tool you use. If you are comparing systems, how to choose auto repair shop management software lists the questions to ask. For turning an inspection into an approved estimate, see digital vehicle inspection: from findings to approved work. For the tax side across provinces, see GST, HST and PST on auto repair invoices by province.

Not legal advice

This article summarizes public guidance for general information and is not legal advice. Rules change and the regulation text governs. Check the sources below and speak with a lawyer or the ministry for your situation.

Last reviewed: October 31, 2026. The Ontario guide, the Safety Standards Certificate page and the CRA rate page were re-read that day; the guide shows “last updated August 19, 2025”. The Ontario guide names Ontario Regulation 17/05 as the governing regulation; read the regulation text for exact wording.

Related reading

• Is Drive Clean Still Required in Ontario? What Emissions Rules Mean for Repair Shops
• Garage Keepers Insurance in Ontario: What It Covers and When a Repair Lien Applies
• Ontario Safety Standards Certificate: Who Can Issue One and What Your Shop Must Do
• Mecano Shop facts: plans, features and limits

Sources

• Ontario.ca, A guide for auto repair businesses
• Ontario e-Laws
• Ontario.ca, Safety standards certificate
• CRA, GST/HST for businesses
• CRA, Which rate to charge (GST/HST)
• AARO