Have you ever thought of bringing your own eggs to your local breakfast joint and asking the chef to cook them for you? It would be weird right? Why then would you supply your own parts to your local mechanic and say install my parts?
With internet shopping, there are so many different platforms to purchase auto parts. There is such a range of quality and pricing that it seems like the right thing to do. Why not purchase your own parts and save a few bucks? You could get stuck with parts in one hand and the phone in the other. You may find it hard to find an auto shop willing to work with you.

Then asking them to cook the eggs for you
Short Answer
You may approach a one-person shop, or you may call a shop with multiple techs. But the answer must always be NO. How they say it may differ. If they have been in the business for a long time your answer will be short and firm.
The short answer can go like “I am sorry, but we do not install customer supplied parts under any circumstances.”
The long answer will always come across as a rant.
The Long Answer
Many customers do not understand why shops have to put a markup on parts. They see parts on-line for $X.XX and they want the shop to beat that price.
With the margins today, a shop’s wholesale price can sometimes be higher than the retail offered online. The price difference between Genuine parts and knock-offs can be extreme. A tech will know when you have to go genuine and when you can try an aftermarket part.
There are fees involved when buying parts for re-sale. Credit card processing fees, ordering time, and accounting on that part are but a few. A shop cannot stay in business without a markup on parts. So even if the markup is a small percentage a shop will often cost more for a part than the price you see online.
Most customers want to supply their own parts to get them cheaper and avoid any markups. Cheap parts are often cheap for a reason. It takes time trying to fit an inferior part. Sometimes an aftermarket part may not fit at all!
Time and experience have taught the shop that chasing the lowest price on a part leaves you chasing your tail. The longevity of the repair goes hand in hand with the quality of the part and the quality of the install.
Warranty
The biggest reason a shop does not want customer supplied parts is the warranty. The shop is responsible for any part that they install. A customer bringing their own parts may push a shop to use a part that is inferior.
If a part fails or has unseen damage in the box before install, it becomes a warranty issue. The part can be easily warrantied from a shop’s regular parts supplier. And a replacement part can be on its way fast. What happens if the part fails and it was purchased by the customer?
They are responsible to put in the warranty claim and chase down the replacement part. This can be a big slow down with a car in the shop taking up workspace. The general public does not do warranty replacements on a regular basis. This makes it take even longer to get a replacement part coming. If you bought the part a long time ago it makes a warranty claim almost impossible.
Every mechanic has a story about one time they were convinced to use a customer supplied part.
They went against their rule and things went south. It is not about being a “nice Guy/Gal” or not. When the customer purchased part fails the shop ends up in a three-way fight with both the customer and the parts supplier. Both often insisting that the part was incorrectly installed. It is no fun for anyone and best not to take the job when it comes to customer-supplied parts.
As a customer
Don’t ask! Please don’t ask to supply your own parts. By bringing your own parts you are going to change your relationship with your mechanic for the worse. You are saying you do not trust them. You are saying they are too expensive. It is like saying they do not know what they are doing and cannot diagnose the problem. What do you do when the tech puts on the parts you supplied, and it does not fix the problem?
If you have already purchased the parts the best answer may be install them yourself. This may not be for you if you do not have the special tools required. Or the space to do the work, or the knowledge to do the job correctly.
Finding a video on YouTube is not always the answer either. We have seen incorrect methods used that will cause more damage to your car than you started with. Do some research, get a factory manual. Find out what the repair involves. Decide if it is worth the savings. Do not forget the time and tools needed to do the job. Do the job right and you will be proud of your accomplishments.

If the job is beyond your skills, see if you can return the parts or maybe resell them. Get the job done at your favorite shop. It’s ok to get quotes from a few shops. Or even tell your mechanic about a great price on a part, but don’t be upset if they cannot match it. Remember the long answer.
Buying your own parts
If you have decided to buy and install your own parts check out our article on buying auto parts. Make sure you get the correct information for your make and model. Understand what is involved before you buy your own parts.
If you go to a shop, read our article, understanding the flat rate labor guide.
1 thought on “Why Auto Repair Shops don’t want you to bring your own parts.”
I like the analogy , “would you bring your own eggs to a breakfast restaurant?”
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