Auto Repair Estimate vs Invoice: Ontario's Rules for Each

Last updated: 2026-11-04 · Rules read from Ontario's guide for auto repair businesses and its car repair rights page. Part VI of the Consumer Protection Act and O. Reg. 17/05 set the rules. This post explains them and isn't legal advice.

In Ontario, the estimate is the written price you give before you touch the car. The invoice is the itemized bill you hand over after the work is done. The estimate comes first because you can't charge for work without one (unless the customer declines it and names a maximum instead). The invoice can't land more than 10 per cent above that estimate. And because the two documents look alike, the province says you must label them clearly.

That's the answer in under eighty words. I wrote the rest for the shop owner, not the car owner. What goes on each document? What do you do when the lift shows you three more problems? And which line in the guide should change how you use your shop software?

Why do customers mix them up?

Because on paper they're almost the same form. The province's guide puts it plainly: "The invoice and estimate may look very similar, so you must clearly label them to avoid confusion" (its words, not mine).

The differences are small and they all point the same way. One is a promise about the future. The other is a record of the past. Reading the guide's two lists side by side, these are the lines I'd flag as the ones that differ.

From the estimate list:

• the date after which it no longer applies, and when the work will be done
• the total amount the customer will be billed, with a disclosure that the final cost can't exceed the estimate by more than 10 per cent
• a list of any parts you plan to install, and if those parts will be new, used or reconditioned

For a full list of estimate requirements, the guide points to section 48 of O. Reg. 17/05.

From the invoice list:

• the odometer reading when the vehicle is dropped off and when it's returned
• the total billed and the method of payment
• shop supplies charged to the customer (and not included in normal operating costs)
• the terms of your warranty for installed parts and labour, or the deemed warranty terms if you don't provide one
• the Consumer Protection Act statement, printed in full

The invoice list is section 51 of O. Reg. 17/05.

The estimate: a price you're held to

Ontario's rule is short. The guide says "You must provide your customer with a written estimate of costs before you can charge them for any work or repairs, except in certain cases" and then names the case. It's the customer who doesn't want an estimate and names a maximum instead. That only holds while the work stays under the maximum.

One more line in the guide catches shops out. Under section 64 of the Act, the estimate must be the same amount whether the customer pays out of pocket or an insurer pays.

I get it: on a busy Monday, writing out every part feels slower than saying "probably around five hundred" at the counter. But the rule says written, and if the CPA applies, skipping the estimate requirements means you won't have a lien under the Repair and Storage Liens Act.

What about the diagnosis fee?

Yes, you can charge for an estimate. Tell the customer the fee before you start. The law treats that fee as covering the examination and the reassembly. It also covers any part damaged along the way (whether you priced it in or not). Can you keep the fee if they say yes to the work? No. The exception is the customer who waits so long that you have to put the car back together to move it. Then the fee stands.

Found three more things on the lift?

This is where the two documents drift apart. The estimate said brakes. Now the car's up and the tie rod end is loose too.

The guide's rule is that "The customer must authorize any work before you can charge them for it". In my reading, that covers every line you add. Did the yes come by phone? Then you record who gave it and when. You also record their contact details, phone number included. So a "yeah, go ahead" on the phone needs a record: the name of the person, the date and time, and their phone number.

And the 10 per cent? In my reading, it isn't room to add work. The guide measures it against the written estimate, so take the estimate's total and add a tenth. That's the ceiling the invoice is held to. The tie rod end still needs its own yes (written, or recorded) before you charge for it.

The car owner's side is on the province's rights page. It has one line I'd want every customer to read: "Never sign a blank work order". A customer who asks you about that line is a careful one. That's not a bad customer to have.

The invoice: a record you can be held to

After the work, you owe a written invoice. On top of the fields in the lists above, it has to carry a fixed statement, printed in full. It opens with "The Consumer Protection Act, 2002, provides you with rights in relation to having a motor vehicle repaired". Then it tells the customer they have a right to a written estimate. The guide says you must "clearly print the following statement in its entirety on the invoice". I'd copy the text from the guide rather than retype it.

The invoice also states the warranty: yours if it's at least as good as the Act's, or the Act's deemed warranty if not. The Act sets a minimum on new or reconditioned parts and the labour to install them: 90 days or 5,000 kilometres, whichever comes first. The mandatory warranty doesn't apply to fluids, filters, lights, tires or batteries. If you already have a written repair shop warranty policy for the counter, check that it doesn't promise less than that floor.

Why should a shop owner care this much?

Because the paperwork is what makes the bill collectable. Miss the disclosure rules and, per the guide, "the agreement you have with the customer is not legally binding unless a court orders otherwise". Its two examples are an estimate or invoice missing required information, and starting work before the customer authorizes it.

It reaches your lien too. If the CPA applies and you didn't follow the estimate rules, the guide says "you won't have a lien" under the Repair and Storage Liens Act. The guide calls the possessory lien "a legal right to keep possession of someone's property until they pay you what they owe you for the repair of their property". Then there are fines. A conviction can cost up to $50,000, or up to $250,000 for a corporation. If you don't comply, the guide says your business goes on the public Consumer Beware List, where it stays for 21 to 27 months.

The software trap nobody warns you about

This is the line I'd underline in the whole guide. "You should maintain a record of the initial estimate. This is important, especially if you use electronic software that converts estimates into invoices."

The warning is about software that converts estimates into invoices. That's handy. It's also how the original estimate quietly disappears. The final invoice cannot be more than 10 per cent higher than the written estimate. If a customer disputes the bill, "the estimate" has to mean what you handed over that morning, not the document it became.

What helps:

• Save the estimate before you convert it. A PDF in the job folder or a printed copy stapled to the paper ticket both work.
• Put the word in the title. "ESTIMATE" and "INVOICE" at the top, big, so nobody has to read the fine print to know which is which.
• Write the yes on the job. Name, date, time, phone, on the ticket or in the RO notes, every time you get one.
• Collect the basics at drop-off. The odometer and VIN are on both documents, so a good repair shop intake form saves you walking back out to the car.

The guide also has a sample sign you can download and print. Your shop must post at least one sign, and it covers estimates, warranties and fees, among other things.

What FixyFlow does and doesn't do here

FixyFlow isn't where your estimates and invoices should live. It runs alongside your RO system, which keeps the parts and the invoicing. The saved estimate belongs there too.

FixyFlow is the auto repair shop software I built for the texting in between. It auto-texts the customer when the job's status changes. That cuts the "is it ready yet?" calls while the car sits between the two documents. If you want the whole drop-off-to-pickup message sequence, it's in the auto repair shop customer communication playbook.

Who shouldn't bother? A two-bay shop whose phone is quiet. Fix the estimate habit above and you're done. If status calls are what eat your mornings, I'd point you at a free trial of field service software (no card needed). After it, your account keeps going on the Free plan, which is 5 jobs/month and 20 SMS. Paid tiers sit on the field service software pricing page.

— Lasse
Built FixyFlow in Collingwood