MPN

An MPN, or manufacturer part number, is the alphanumeric code that a manufacturer assigns to a specific product or part to identify it within its own range. In product catalogs, the MPN is one of the core product identifiers: combined with the brand name, it lets retailers, marketplaces, comparison engines and distributors recognize that different listings describe the same physical item.

Unlike a barcode number, an MPN is not issued by a central authority. Each manufacturer designs its own numbering scheme, so an MPN is meaningful only in combination with the brand. This makes the MPN especially important for spare parts, electronics, tools and industrial goods, where buyers often search for the exact part number printed on a component or in a manual.

How an MPN identifies a product

An MPN identifies a product by pointing to one entry in the manufacturer’s internal catalog. The manufacturer decides its structure: some codes are purely sequential, while others encode the product family, size, color, voltage or revision in segments of letters and digits.

Because the scheme is private, two manufacturers can use the same string for unrelated products. The pair brand plus MPN is therefore the real identifier, and catalog systems should store and compare both fields together. An MPN printed on the product, its packaging or its datasheet is the authoritative value, and retailers should copy it exactly rather than reformatting it.

The table shows typical patterns of manufacturer part numbers and what their segments can express.

MPN compared with SKU, GTIN and other identifiers

The MPN is often confused with the SKU and the GTIN, although each identifier is created by a different party for a different purpose. A well-structured catalog stores all of them in separate fields.

A GTIN is the number behind EAN and UPC barcodes, with 8, 12, 13 or 14 digits and a check digit, and it is licensed through the GS1 system. An MPN has no fixed length, no check digit and no registry. Many products have both, but some, such as custom parts, industrial components or older items, have only an MPN.

Why MPNs matter in product feeds and search

MPNs matter because matching engines use them to group offers. Comparison sites, shopping ads and marketplaces try to place every seller’s offer for the same item on one product page, and they rely on identifiers rather than titles, which vary widely.

• Shopping feeds: when a product has no GTIN, feed specifications commonly ask for brand and MPN as the alternative identifier pair.
• Structured data: the schema.org mpn property allows product pages to expose the part number to search engines.
• Site search: business buyers often paste a part number directly into search, so the MPN must be indexed and searchable, including common variants without hyphens.
• Distributor data: wholesalers and electronic component distributors build cross-references between MPNs of compatible parts.

Missing or wrong identifiers usually lead to weaker visibility in shopping channels, because the listing cannot be matched to the correct catalog entry and may be treated as a lower-quality offer.

Managing MPNs in a catalog

Managing MPNs well requires clear rules about source, format and variant level. In a PIM or catalog management system, the MPN should be a dedicated attribute that is filled from supplier data, validated and never overwritten with internal codes.

Many teams store a normalized search key next to the original value, for example the MPN in uppercase without spaces, hyphens and slashes. The original value is displayed and sent in feeds, while the normalized key supports duplicate detection and search.

Common MPN errors

Most MPN problems come from data entry shortcuts and from mixing up identifiers. They are easy to prevent once catalog teams recognize the patterns.

A particularly costly mistake is assuming that equal MPNs from different brands are the same product. Duplicate detection must always compare the brand as well, otherwise unrelated items can be merged in the catalog.

Explained without jargon

An MPN is the model number the maker gives a product. It is the code printed on a printer cartridge, a car part or the back of a router that tells exactly which version it is.

Shops use it so that a customer searching for that exact code finds the right item, and so that the same product sold by different shops can be recognized as identical. Because every maker invents its own codes, the brand name and the MPN always belong together.

A typical use case

An online retailer of heating spare parts carries about 18,000 items, many of which have no barcode at all. Its feed to a shopping channel initially sends only titles and internal SKUs, and a large share of products is shown with limited visibility because they cannot be matched to known products.

The catalog team imports the original part numbers from supplier price lists, stores them in a dedicated MPN attribute with the brand, and adds a normalized search key. Installers can now paste a part number from a boiler manual into site search and find the exact pump or valve. In the shopping feed, products are submitted with brand and MPN, and more of them are matched to existing product pages, which increases impressions for long-tail spare parts.