Google Shopping

How MPNs Help Solve Product Identifier Issues in Your Feed

0 · by Dennis Moons · Updated on 28 March 2023

In online commerce, products have references consisting of a series of numbers (or other types of code) known as unique product identifiers or (UPIs). There are a number of these UPIs out there, and sometimes it’s hard to navigate the use of all the different acronyms for product identifiers, like GTIN, MPN, UPC, EAN, ISBN and others.  

In this article, we’ll cover the basics of Manufacturer Part Number (or MPN) as a product identifier. We’ll explain what it is, how it affects brand visibility on Google, Amazon, and eBay, and what to do when retailers are asked to provide an MPN.

Manufacturer part numbers have other uses as well, and we will quickly touch upon those too. 

Let’s dive into it.

What Is a Manufacturer Part Number?

The Manufacturer Part Number (MPN) is a number that’s assigned to a product by the manufacturer who made it. It’s similar to other unique product identifiers, like GTINs, in that it helps to distinguish between different versions of the same product, or between different products of the same brand.

Unlike unique product identifiers, which are international standards, MPN is not. This means that the manufacturers decide what the MPNs for their products will look like.

MPN Format

MPNs can consist of both digits and letters (don’t let the “number” in their name fool you). The logic behind the use of digits and letters is not regulated and it’s up to the manufacturer.

This is quite different from other unique product identifiers (UPIs) with a standardized format. For example, in a GTIN, the digits convey information about the product, while with MPNs, this isn’t always the case.

Randomly Assigned MPNs Are Still Helpful

Even though the string of digits and letters in MPNs can be random, it’s still very helpful for sharing information between organizations, like a retail center and an authorized service.

For example, if the product is “gray polycarbonate aft deck window for Leopard Catamaran 2007”, a seemingly random MPN like “BHFOLK 357” can make life much easier, as long as both parties know what it refers to. Usually, manufacturers include the MPNs in their online catalogs, so these identifiers are easy to find.

MPNs are not the same as model names, because sometimes that’s not specific enough to identify a product. Models may differ based on the manufacturing date, or model names may be too generic to cover items with slightly different technical specifications.

How are MPNs used?

MPNs help shopping platforms and search engines match search queries with products and serve as another identifier that points to a specific item.

Traditionally, Manufacturer Part Number was crucial for aftermarket part industries that trade in all types of hardware – vehicles, computers, machines, or special equipment. This doesn’t mean that online merchants who handle different categories of products don’t need MPNs to make a sale – quite the contrary.

The logic is the same whether you sell replacement parts for cars or ink cartridges for fountain pens.

Benefits of Using MPNs

There are a lot of benefits to using MPN as identifiers for items in your product catalog. We will touch on some of them below.

MPNs Ensure Customer Satisfaction

Even though shopping platforms primarily use GTINs to identify a product, MPNs (and [brand] on Google), provide an additional way to verify that a product is original and not counterfeit presented as an original. Also, it makes it easier for customers to find the right product, including detailed specifications or some other product details.

So, MPNs contribute to customer satisfaction because the buyer gets the exact item they’re looking for.

MPNs Helps Match Searches With Products

Unique product identifiers are indexed in search engines and, in terms of marketing, the MPN is another layer of product ID that makes it easier to show the most relevant product ad to a user.

Moreover, it can be used to identify a specific product from all the products by the same manufacturer (as is the case on eBay), especially for sellers with a big inventory. The idea is to pinpoint the exact product so that shopping platforms can better serve users/customers when searching through a product catalog in a database.

MPNs Improve Campaign Performance

MPNs also help improve products’ placement and brand visibility on search engines (especially on Google). This, along with better matches for the search queries, results in higher click-through rates, and ultimately more conversions.

In a way, by complying with the requirement for an MPN identifier, you will make more sales.

MPNs Facilitate Better Handling of Products

Since MPNs are publicly available product references, they can make it easier to move stock both internally and externally. It’s another go-to reference used by everyone in a supply chain, along with GTINs or barcodes.

This is even better if MPNs are assigned using some logic. But even if they are completely random, they add another way to further streamline distribution and general logistics.

Let’s check how popular shopping platforms use MPNs.

MPNs and Google Shopping

In Google Merchant Center, the use of MPNs is optional. That being said, sellers are encouraged to add a Manufacturer Part Number for each product in their inventory. MPNs are only required for those products for which the original manufacturer hasn’t provided a GTIN.

Google uses MPNs along with the brand attribute and GTINs to match products with search queries. If you don’t have a valid MPN, it’s not recommended to enter a placeholder value (made up on the spot) just to close the notification about an issue with a product identifier in your feed.

If you do provide MPNs, it’s advised to provide one per item because the MPN will pinpoint different variations of the same product (like size, color, etc.). This will be used by Google to improve its service.

MPNs and Amazon

Amazon has something that’s called Amazon Standard Identification Numbers (ASIN) and different UPIs can be used as a product reference. Of all these, GTINs (or UPCs, EANs, and ISBNs) are the most important, while MPNs are optional for some product categories.

This has to do with the items sold on the platform. For example, ISBNs are used for books, SKUs are excepted for merchandise (like a t-shirt or a mug), and MPNs are recommended for aftermarket products (car parts, electronics, etc.).

MPNs and eBay

eBay has introduced ePid, or eBay Product Identification, to make sense of the products in its own catalog and provide better product pages. ePIDs don’t replace UPIs, so GTINs, MPNs, and other identifiers are recommended.

Over the years, eBay faced difficulties in implementing UPIs as a requirement for all of its sellers, and as a result, the rules on product ID are more lax (or at least not mandatory). The shopping platform offers perks, like detailed product reviews, price alert feature, etc., to sellers who provide identifiers as an incentive to comply.

Following on that, sellers who have MPNs in the product title and in the bullet points are more likely to show up as a relevant result to a query.

How To Find the MPN of Your Product?

Advertisers don’t manufacture products, so why should they care about MPNs? Well, this quickly changes when an advertiser receives a notification about an error in their product feed: “limited performance due to missing identifiers – missing MPN.” The issue can be easily fixed if you provide a valid MPN.

But where do you find MPNs? You can start by checking the product packaging – sometimes the Manufacturer Part Number is included, despite the use of a barcode (or a GTIN) to identify the product.

If it’s not there, the best way to find an MPN would be to check with the manufacturer or the supplier. Often, the MPNs are included in product catalogs, on manufacturers’ websites, and in online databases; however, this works better with certain categories of products, like hardware, because it’s considered important info.

If the manufacturer hasn’t made their MPNs publicly available, you can contact them directly to check.

How Do You Get an MPN?

If you are both the manufacturer and the advertiser, there’s no one else to turn to. Fortunately, you can create an MPN right away by entering alphanumeric values in the required fields.

Sometimes, manufacturers use their SKUs (which are meant for internal purposes) to double as MPNs as well. This is not possible for UPIs like GTINs, but it can pass for MPNs.

Also, nothing stops manufacturers from using an old MPN to refer to a completely new product.

If you, as a manufacturer, want to introduce some logic to assigning MPNs for different items, that’s up to you.

Do Customers Use MPNs?

When users know the exact product they need, sometimes they perform searches using MPNs. This is indicative of high purchase intent, and advertisers should make the most of it.

Just note that this is more likely to happen for a specific type of product, like a computer component, as people usually don’t look up products like t-shirts by their MPNs.

MPNs in the Google Manufacturer Center

Just as there is a Google Merchant center for online retailers, there is a Google Manufacturer Center for the manufacturers. Through the Manufacturer Center, brands and manufacturers can provide detailed info about their products.

As we already established, the MPN helps Google to identify the product – this is beneficial on multiple levels all across the Google product catalog. These benefits stem from the improved matching of queries with products. The end result is a more detailed product description or more relevant product ad for Google’s users.

And given the obscurity surrounding Google’s algorithms, MPNs are probably used in many other ways.

Let’s check how MPNs compare to other product identifiers.

Alternative Product Identifiers

We will put MPN characteristics alongside other widely used product identifiers, so you can better note the differences.


Or Global Trade Item Number, is an internationally standardized product identifier. It’s issued by GS1, and it costs up to 30 USD to get one. On the other hand, MPN is free and up to the manufacturer. So, these two identifiers can often be found one beside the other.

Learn how you can find the GTIN number online.


The Universal Product Code, is the same as a product barcode, and it was established to identify a product at checkout, including details like brand, product, size, or color. It’s what we all see when buying items at a grocery supermarket and is equivalent to GTIN-12 format.

Sometimes, manufacturers use UPC from discontinued products as an identifier for new products – as a way to avoid paying for a new GTIN. Also, manufacturers can use the same UPC for different variations or specifications of the same product (for example, same item, different color).

In this case, MPNs are actually more reliable in providing product data because they don’t cost anything – the manufacturer can issue one for each iteration of a product.

Plus, if one of these identifiers is missing, the other can be used to identify the product. This applies particularly to product catalogs of shopping platforms, when product data is incomplete.


The International Standard Book Number, is an identifier exclusively used for books and publications standardized in the GTIN-13 format. It’s most relevant on Amazon and similar publishing platforms. Moreover, on Amazon, the use of ISBNs and MPNs is reserved only for products in the corresponding category (i.e. books vs retail products), so you can’t mistake one for the other.


The European Article Number is expressed in either the GTIN-8 or the GTIN-13 format. It’s also known as International Article Number (IAN) and is used for retail products outside North America.


Or Japanese Article Number, is virtually the same as EAN, the only difference is the prefix which is “45” and “49.”

So, what applies to GTIN in general, applies to UPC, EAN, and JAN as well.


Or Stock Keeping Unit, is a product identifier for internal purposes. As such, it can follow any logic for assigning numbers, it depends on the handler (manufacturer, distributor, or other). Since an SKU is a product reference that is already in use, sometimes manufacturers simply extend its usage and enter the SKU as a MPN on shopping platforms.

However, note that SKUs are not standardized, nor internationally adopted product identifiers, so search engines like Google will not be able to use SKU as a reference for products in traffic analysis. So, even if you assign a SKU as an MPN to make things easier for you, it won’t mean anything to shopping platforms.

MPNs Are an Important Product Identifier

Even though MPNs are not as official and sanctioned as GTINs, they still play an important role in identifying products.

When you need to solve a “product identifier” issue in your shopping feed, providing an MPN might help. To find it, check online catalogs or contact the manufacturer.

Once provided in a product database, MPNs will help in driving conversions up due to improved matching of queries with specific products.

Dennis Moons

Dennis Moons is the founder and lead instructor at Store Growers.

He's a Google Ads expert with over 12 years of experience in running Google Ads campaigns.

During this time he has managed more than $5 million in ad spend and worked with clients ranging from small businesses to global brands. His goal is to provide advice that allows you to compete effectively in Google Ads.

Follow him on Twitter or LinkedIn.


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