A garage invoice can have 15 lines, half of them full of abbreviations. This guide explains what each section means, what's normal, and the warning signs of a shop that abuses. We're talking as a parts store that sells to mechanics every day — so we know what parts actually cost.
The 6 sections of a typical invoice
1. Vehicle identification
Make, model, year, mileage, VIN (17 characters). Verify everything is correct — a VIN error can complicate a warranty later.
2. Work description
The heart of the invoice. Should describe in plain languagewhat was done. If it just says "Engine diagnosis" with no details, ask for more.
3. Parts
List of parts used with quantity and unit price. Each part should have:
- Part name or number
- Quantity
- Unit price
- Line total
Garages typically buy parts at wholesale and bill them with a markup (30-60% is normal). That's not theft — it's their business model. But a $300 pad billed at $600 is excessive.
4. Labor
Hours × hourly rate. Quebec labor rates range from $85/hour (independent garage) to $170/hour (dealership). Hours are calculated from a time guide (AllData, Mitchell, Motor), not actual time. If the guide says 2 hours and the mechanic finishes in 90 minutes, the bill is still 2 hours.
Seeing "diagnosis" at 1 hour + "replacement labor" at 2 hours, total 3 hours, is normal. Some shops bill diagnosis separately, others include it if you do the repair.
5. Shop fees
A murky and potentially abusivecategory. Some shops add 5-10% "shop supplies fee" (grease, rags, solvents). Others bill "environmental fees" for used-oil disposal. A $5-15 total is normal. More than 10% of the subtotal is excessive. Ask what it covers specifically.
6. Taxes
GST (5%) + QST (9.975%). On parts AND labor. Quebec QST is calculated on the subtotal including GST ("tax on tax" technically).
Warning signs
A repair that turns into a rebuild
You arrive for a brake pad, you leave with pads + rotors + calipers + hoses + fluid. Sometimes it's legitimate (everything really was due), sometimes it's upselling. Always ask to see the worn parts.
"OEM" parts that aren't
Some shops bill at OEM prices but install aftermarket parts. Ask for the box or proof. If the mechanic refuses to show the packaging, that's suspicious.
Diagnosis billed before authorization
A diagnosis typically costs 1 hour. If it hits 3-4 hours without anyone calling you for authorization, that's a red flag. In Quebec, the Consumer Protection Act requires a written estimate before exceeding the discussed amount by more than 10%.
"We also had to change X" without photo
Always ask to see the failed part before it's tossed. A good mechanic is happy to show it.
Labor hours way above the time guide
If billing says "5 hours" for a job the published guides (available online via AllData) list at 2.5 hours, ask why. Sometimes there's a legit reason (rusted bolts, awkward access), sometimes not.
Your rights in Quebec
- Free written estimate required for any work over $100 (Quebec Consumer Protection Act).
- No more than 10% over the estimate without your written authorization.
- The old parts belong to you — ask to keep them if you want to verify.
- Minimum legal warranty on repairs — parts often have a manufacturer warranty, and labor is typically guaranteed 3 months to 1 year.
How to avoid bad invoices
- Always ask for a written estimate before any work, with labor AND parts separated.
- Ask the mechanic to call before adding any unplanned work.
- Ask to see the worn parts.
- For expensive repairs (more than $1000), get a second opinion.
- Keep your invoices — useful for warranty, resale, and maintenance history.
Why we wrote this guide
We've been selling auto parts for years. We see both sides: honest mechanics charging a fair price, and occasionally customers coming back angry because we've seen their invoice with $300 of "shop fees." An informed customer makes better choices, and in our industry, that helps everyone — including the good garages who stand out more easily.
Need parts for your own work?
If you do your own repairs (or your garage lets you bring your own parts), call us. We sell at the same prices we sell to garages. See our auto parts in Laval, our brakes in Laval, or our DIY oil change guide.