# Manufacturer part number

Category: [E-Commerce SEO](https://seo-geo-glossary.com/en/glossary/category/e-commerce-seo/) › [Product data, feeds & Shopping](https://seo-geo-glossary.com/en/glossary/category/e-commerce-seo/product-data-feeds-shopping/) · Also known as: MPN, manufacturer part number, part number

The **manufacturer part number (MPN)** is the identifier a manufacturer assigns to a product or part. In SEO the term refers to the `mpn` attribute in Google's product feed and in Product markup.

## What does Google need the MPN for?

Google's Merchant Center help states that the MPN is required for all products without a manufacturer-assigned GTIN. It is optional for custom-made items such as art or handmade goods. The attribute allows up to 70 characters. The help page says to provide an MPN only when you are sure it is correct and not to guess or make up a value. For new products without assigned product identifiers, the identifier_exists help page says to submit `identifier_exists` as "no".

For variants, each normally has its own MPN, although different sizes of apparel often share one. For bundles and multipacks the manufacturer's MPN applies if the manufacturer created the bundle. If you assembled it yourself, use the MPN of the main product.

In Product markup, `mpn` is a recommended property alongside `gtin` and `sku`.

According to Google, an MPN uniquely identifies a product among all products from the same manufacturer. It is therefore not necessarily unique across manufacturers and is normally paired with the brand (an assessment). A SKU, by contrast, is a number a seller defines for its own inventory, and a GTIN is a globally unique number.

## Example

```json
{
  "@type": "Product",
  "name": "Brake disc 280 mm",
  "brand": { "@type": "Brand", "name": "Example Brand" },
  "mpn": "BD-280-FA"
}
```

## FAQ

**What is the difference between GTIN and MPN?**
A GTIN is unique worldwide and used across retail. An MPN is the manufacturer's own number and identifies a product reliably only together with the brand.

**What is the difference between a SKU and an MPN?**
A SKU is the seller's internal code for inventory. An MPN is assigned by the manufacturer and stays the same across sellers.

## Related terms

- [GTIN](https://seo-geo-glossary.com/en/glossary/gtin/index.md)
- [Google Merchant Center](https://seo-geo-glossary.com/en/glossary/google-merchant-center/index.md)
- [Product schema](https://seo-geo-glossary.com/en/glossary/product-schema/index.md)
- [Product feed](https://seo-geo-glossary.com/en/glossary/product-feed/index.md)
- [Product variants](https://seo-geo-glossary.com/en/glossary/product-variants/index.md)

## Sources

- [MPN [mpn] – Merchant Center Help](https://support.google.com/merchants/answer/6324482?hl=en)
- [Merchant listing (Product, Offer) structured data – Google Search Central](https://developers.google.com/search/docs/appearance/structured-data/merchant-listing)
- [Identifier exists [identifier_exists] – Merchant Center Help](https://support.google.com/merchants/answer/6324478?hl=en)
- [What is an MPN? – DataFeedWatch (secondary)](https://www.datafeedwatch.com/academy/mpn)

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Last updated: October 7, 2026
URL: https://seo-geo-glossary.com/en/glossary/manufacturer-part-number/