Back to Blog

Manufacturer Part Number [Updated 2021]

Jeff Cohen
Jeff Cohen Author

If you’ve ever needed specialized electronics, replacement parts, tools for home improvement, modifications for auto repairs, or other specialty items for DIY projects, you know the frustration of shopping for these specific goods online. Even what seems like a simple light bulb can be challenging to find when you need the part to fit just right. And if you’re looking to replace a part on an older model, forget about it. You’re gonna need an MPN.

What Is a Manufacturer Part Number (MPN)?

Simply put, the MPN is a unique identifier set by the product’s manufacturer to differentiate it from similar parts and counterfeits. It helps manufacturers and sellers identify and manage stock levels and it puts buyers’ minds at ease because they know that they are getting the right component. 

For Amazon, MPN is an optional field in the inventory listing file and not applicable to all merchandise. For instance, a sweater has a SKU, not an MPN. A book has an ISBN, not an MPN. And what is a UPC? Not the same thing as an MPN. Confused yet? Us too, which is why we put together this handy-dandy table to help decipher the alphabet soup of product codes:

(Manufacturer Part Number)

A unique code issued by manufactures to identify a product
what is an MPN
(Stock Keeping Unit)

A series of numbers used by businesses to track their inventory internally
what is a SKU
(International Standard Book Number)

A product code used only for published books, texts, or other literature.
What is an ISBN
(Universal Product Code)

The common barcode, used in most countries to track retail items.
what is a UPC

The Manufacturer Part Number is really only relevant in certain cases. If you’re selling parts for automotive & powersports and consumer electronics, for example, the MPN is crucial. Consumables and lifestyle products like toys, clothing, won’t really benefit.

Selling electronics or automotive good online has special considerations, so you should check out the selling guides from our partners:

Although it seems difficult to start manufacturing products for Amazon, there are tools to help. Consider using Alibaba for manufactured products.

One detail that is easy to master? The MPN.

MPN: How One Little Number Can Drastically Improve Your Amazon Sales

The internet has made shopping much easier by connecting buyers with a world of previously out-of-reach resources. Often, the best places to find specific parts are directly from the manufacturer or from eBay. However, manufacturers often don’t want to deal directly with consumers or they are reluctant to sell single parts, and eBay transactions sometimes leave buyers hanging with sketchy sellers and dud deals. Enter, the Amazon sellers who are willing to dig into Manufacturer Part Number (MPN) and include this little detail in their listings.

Side Note:

Unfortunately (for sellers and for shoppers), not all merchants have embraced MPN where applicable, creating three problems.

1. Difficulty finding exactly what shoppers need, ending in a poor user experience
2. Reducing sellers’ potential conversions when buyers are afraid to order the wrong part
3. Increasing the likelihood of returns when the wrong part is ordered

The Benefits of Including MPN:

As an expert Amazon seller, you know that the more you complete your Amazon product listing, the easier it is for customers to find your product. Although this small code seems trivial, it could lead more shoppers to find your product. And those shoppers, who are looking for your very specific product, are far more likely to convert.

what is manufacturer part number in amazon seller
  • Discoverability: MPN is a field that is indexed by Amazon and by Google, which means that if you include it in your listing, it will be picked up and matched by both search engines and displayed in results. This gets your product found fast and without ambiguity.
  • Conversion: A replacement part or a highly specific piece of equipment isn’t an optional item or one where a shopper browses for a better match or a different color. These sorts of items are what the shopper needs and no other part will do. When you drill down to MPN specificity, and that MPN is the exact term for which the user is searching, you are almost certain to achieve the conversion because the shopper has undoubtedly found the right product.
  • Fewer Returns: When you sell the right product to the customer who needs that exact item, you won’t have many (or any) returns. This saves you time and money and it helps your seller rankings and ratings. Amazon loves a low return rate.
  • Product Reviews: With no doubt about the compatibility of the item, you are likely to get a good review from the buyer. Shoppers are immensely appreciative of those sellers who can meet their highly specific demands. They also appreciate being able to fix or restore items by replacing parts rather than having to purchase an entirely new larger, more expensive product.
  • Repeat Customers: A shopper who is a serious stereo enthusiast or DIYer often needs multiple specialty parts or single parts in multiple quantities. A person working on a classic car might need four of something if he or she is working on wheels. A person replacing bulbs in commercial ceiling fans will likely buy more than one bulb so that he or she has spares on hand when the next bulb needs replaced. When a customer knows that a seller has the right parts, that customer will often buy in quantity and return to that seller for reasons of ease and trust. Why buy from another seller when you know you can get the right part without doubt or hassle? That’s the beauty of MPN.

Go Beyond Listing MPN In the Optional Field

If you’ve got MPN-applicable merchandise, including that detail is great, but you can still go further and get more out of it.

  1. First and foremost, double-check that you’re listing your MPN correctly. The confusion here undoes all of the good of using the MPN in the first place.
  2. Don’t just include the MPN in the Manufacturer Part Number field in the inventory listing. Add the MPN to the title and bullet points. If it has dashes in it from the manufacturer, list it with dashes and also without punctuation so it doesn’t trip up the buyer or the search.
  3. Show, as well as tell, your buyer that the part is undoubtedly the right one; include the MPN in one of your detailed photos of the part. Usually, the MPN is stamped on the part, and seeing that will boost a customer’s confidence.
  4. If you know that a particular part is compatible with many products, list those other products as well so you can pick up traffic from buyers who might not know that what you have to offer will do the job for them.

If you are selling auto parts online, you want to take your business a step further and open an online store of your own, customized to your unique business needs. With a wealth of options and tools that X-Cart has to offer, including search by MPN or by UPC, you’ll never be locked into one way of doing business.

Len Stavish

“With X-Cart shopping cart, selling auto parts online made easy.”

Len Stavish, Chief Operating Officer at

Using the Manufacturer Part Number Eliminates Guesswork

Example: I was searching for a replacement wheel cap cover for a 2016 VW Jetta Sport 1.8. My initial search was done without knowing the part number and it led me to some totally irrelevant results. Adding my vehicle to my Amazon Garage helped, but even then I was seeing parts that I knew were not compatible.

I had to do a search, but which search terms should I use? “VW wheel cap cover”? “Volkswagen hubcap emblem”? Wait, why are Toyota parts showing up as matches now? No, I am not looking for sport floor mats. (Sellers can solve this search-verbiage problem with a tool like Seller Labs Pro, which tells you the exact words that shoppers are using to search and how to use those as your listing keywords.)

Finally, I got to what I thought what the right part but I wasn’t entirely sure. I didn’t want to order the wrong item and have to deal with a return, so I found the part number from an PDF technical manual online.

Then I was able to search using the precise Manufacturer Part Number, get an immediate perfect match, and order the part I needed. And the seller got the sale. MPN, FTW.

Want more Amazon Sales?

If you’re looking to boost conversions, accelerate sales velocity, and get your products ranking higher on Amazon, talk to one of our Amazon experts, or try our suite of self-service tools.

Want more Amazon sales?

If you’re looking to boost conversions, accelerate sales velocity, and get your products ranking higher on Amazon, talk to one of our Amazon experts, or try our suite of self-service tools.

Jeff Cohen
Jeff Cohen Principal Evangelist of Advertising API at Amazon

Jeff has more than 15 years of eCommerce experience. He is the Principal Evangelist of Advertising API at Amazon and a frequent keynote speaker at various business related conferences. He's widely regarded as an industry expert who is asked to share actionable intelligence on how Amazon works and how sellers can improve their business.


Ready for Amazon Prime Day 2022?

Grab our Prime Day Preparedness Checklist to make sure you are. Plus, get a bonus Promotions Cheatsheet!

    Breaking Breaking

    Effective Jan 17, Amazon announced their first FEE increases for 2023 and it is basically everything. Full details here. All exact % changes are noted as well.

    In-depth video and blog post to follow. Subscribe to fee change updates here.


      Thank You!